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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Activity report
Institut Mittag-Leffler is a Nordic research institute for mathematics. It was founded in 1916
by Professor Gösta Mittag-Leffler and his wife Signe, who donated their magnificent villa
with its first-class library for the purpose of creating the Institute that bears their name.
The Institute is today an active international center for front-line research in the
mathematical sciences, operating under the auspices of the Royal Swedish Academy of
Sciences. It enjoys the economic support of national funding agencies from all the Nordic
countries, as well as of some private foundations. The main activities at the Institute are
the research programs and the publication of two research journals.
The Institute conducts semester-long programs aimed at research in some area in pure or
applied mathematics of current interest. The ambition is that over time all areas of current
interest to mathematicians in the Nordic countries are served. The programs during the
current 10-year period – past, present and future – are:
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Probability and conformal mappings, fall 2001 and spring 2002.
Partial differential equations and spectral theory, fall 2002.
Mathematical control and systems theory, spring 2003.
Noncommutative geometry, fall 2003 and spring 2004.
Queuing theory and teletraffic theory, fall 2004.
Algebraic combinatorics, spring 2005.
Wave motion, fall 2005.
Algebraic topology, spring 2006.
Moduli spaces, fall 2006 and spring of 2007.
Stochastic partial differential equations, fall 2007.
Several complex variables, spring 2008.
Geometry, analysis, and general relativity, fall 2008.
Discrete probability, spring 2009.
Mathematical logic: Set theory and model theory, fall 2009.
Dynamical systems and PDEs, spring 2010.
Quantum information theory, fall 2010.
Algebraic geometry with a view to applications, spring 2011
Complex analysis and integrable systems, fall 2011.
Geometric and analytic aspects of group theory, spring 2012.
The subject area for each research program is decided circa 2 1/2 years in advance by the
board of the Institute, based on submitted proposals. An international evaluation
committee is appointed, which meets at the Institute and conducts interviews with the
prospective organizers as a basis for the recommendations submitted to the board.
Each research program is led by an organizing committee. Based on the recommendations
of this committee the Institute invites senior and junior mathematicians to come and work
together at the Institute. The senior participants are chosen among the internationally
leading mathematicians in the given area. To the junior
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
participants, typically recent Ph.D.s, we offer fellowships, open to everyone to apply for.
Mathematicians from the Nordic countries are given a slight priority, however we make
sure that scientific caliber and a good mixture of talents and backgrounds have top priority,
to optimize the creative environment at the Institute.
During 2009 there were a total of 151 visiting researchers, working a total of 272.5 manmonths at the Institute as part of the following programs:
Discrete Probability, spring of 2009
Organizing committee:
Sven Erick Alm, Uppslala
Olle Häggström, CTH, Göteborg
Svante Janson, Uppsala
Kurt Johansson, KTH, Stockholm
Jeff Steif, CTH, Göteborg
Mathematical Logic: Set Theory, fall of 2009
Organizing committee:
Dag Normann, Oslo
Erik Palmgren, Uppsala
Jouko Väänänen, Amsterdam and Helsinki
Hugh Woodin, Berkeley
Detailed reports and documentation on these programs can be found later in this annual
report.
The research programs are conducted in a way that recognizes the immense value of
having the time and the freedom to follow one's research interests wherever developments
lead rather than having to deliver on predetermined goals. For this reason we require of all
participants that they stay at least one month, to ensure time for substantial work.
An aspect of the programs that is emphasized is to provide good postdoctoral training to
the junior participants. Special seminars and minicourses are given specifically for them. In
addition to these area-specific research programs we have the RIP program (Research in
Peace), which allows Nordic mathematicians to spend time at the Institute for independent
research.
The Institute publishes two journals, Acta Mathematica (founded in 1882) and Arkiv för
matematik (founded in 1903). Information about the journals is given on page www.mittagleffler.se/publications/. Acta Mathematica has won a standing as one of a handful of
journals generally considered to be the most important ones among all mathematics
research journals.
Institut Mittag-Leffler is an active participant in international scientific life. In particular, it
participates in international networks of research institutes in mathematics. For instance,
we belong to ERCOM (European Research Centers on Mathematics), a network of European
sister institutes. We also belong to EPDI (European Post-Doctoral Institute), a collaboration
between 9 institutes for jointly awarding postdoctoral fellowships to Europe's most
promising young mathematicians.
During 13-14 March Institut Mittag-Leffler hosted the annual ERCOM meeting. 30 directors
and administrators representing 21 of the 26 ERCOM member institutes met in Djursholm
to discuss matters of common concern and to share information.
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Participants at the ERCOM meeting
The efforts to improve the Institute's financial situation have led to some small progress
during 2009. Being a Nordic institute, we benefit from contributions from all Nordic
countries (including Iceland). On 22 September a Nordic meeting was held at the Institute
to discuss its financial basis. Representatives from the national research councils of
Denmark, Finland, Norway and Sweden were present, as well as mathematicians from
these countries. The meeting indicated a general willingness from our neighboring
countries to increase their contributions.
Institut Mittag-Leffler extends its warm gratitude to all organizations and individuals who
via grants and contributions of various kinds have made the work of the Institute possible
during the year 2009.
Anders Björner
Director
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Contributors
The Institute is very grateful to the following organizations and individuals for contributions
and support during 2009:
The Swedish Research Council (Vetenskapsrådet)
Academy of Finland
The Danish Research Councils
The Icelandic Mathematical Society
The Research Council of Norway
Acta Mathematicas fond
Barbro Osher Pro Suecia Foundation
Department of Mathematics, University of Oslo
European Science Foundation's Set theory Research Network INFTY program
Fonden ”Till bröderna Jacob och Marcus Wallenbergs minne”
Stiftelsen G.S. Magnusons fond
The Anna-Greta and Holger Crafoord Fund
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Discrete Probability
Scientific report 2009 spring
The spring 2009 Mittag-Leffler programme on discrete probability saw intense work in the
intended broad spectrum ranging from, on one hand, basic probabilistic objects such as
Markov chains, random walks, random graphs and random matrices, to, on the other hand,
applications in computer science, statistical mechanics and the modeling of epidemics and
social networks.
A central meeting point for the participants was the seminar taking place Tuesdays and
Thursdays; a total of 74 seminars were delivered. The seminar was very lively and led
(together with the frequent more informal discussions during coffee breaks, in corridors
and in hallways) to several unexpected collaborations. Recurrent themes covered in the
seminar from a variety of angles include, for instance, the Ising model, Poisson processes,
sorting and selection algorithms, Gaussian unitary ensembles, percolation models including
dynamical percolation, different aspects of random graphs, and random walks with various
(self-)interactions or in random environments.
There were a number of research projects completed in the area of percolation, particle
systems and related topics. John Wierman, who participated the entire semester, showed in
collaborative work that certain pairs of 2-dimensional lattices have the same critical
exponents. Remco van der Hofstad succeeded in uncovering the structure of the size of the
largest component for nonhomogeneous graphs; the critical quantity turns out to be the tail
behavior of the degree. Jonathon Peterson and Timo Seppäläinen obtained very precise
results concerning current fluctuations for a system of random walks moving in a common
fixed random environment; it turns out that the fluctuations are occurring at two different
scales. Maria Deijfen and Olle Häggström constructed an example of a percolation model
where the speed of a biased random walk on the cluster is not monotone in the bias; this
monotonicity is believed to hold for i.i.d. percolation. This example therefore shows that the
i.i.d. assumption is critical.
One important area studied during the program was random graphs. In particular, progress
was made on several fronts in the study of inhomogeneous random graphs, with
contributions in the form of completed preprints by Tom Britton, Maria Deijfen, Remco van
der Hofstad, Svante Janson, Mathias Lindholm, Tomasz \Luczak, Ilkka Norros, Oliver Riordan
and Tatyana Turova. As an important example we would like to mention the result by
Tatyana Turova describing the distribution of the sizes of the largest components of an
inhomogeneous random graph in the critical window; this is a major
generalization of a well-known result by Aldous (1997) for the standard Erdös-Rényi random
graphs. The result turns out to be essentially the same as in the standard case, provided a
third moment is finite.
Other random graph problems studied include the diameter in the standard random graph
process (\Luczak and Taral Guldahl Seierstad); high-dimensional models (Markus
Heydenreich and van der Hofstad); connections to graph limits (Janson); recursive directed
graphs (Luc Devroye and Janson); correlations in randomly oriented graphs (Sven Erick Alm
and Svante Linusson); random lifts and large deviation estimates (Janson and Andrzej
Rucinski).
The demographics of the programme was very broad agewise, and somewhat tilted
genderwise. A core group of young postdocs staying throughout the programme was of
particular importance for holding it together, while more senior participants (with a few
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
exceptions) tended to stay for only parts of it but made important contributions
nevertheless.
At present 37 preprints are listed as resulting from the programme, but this is not entirely
representative as many advances made during the programme are yet to be written down
in preprint form. A key participant from a scientific point of view was Svante Janson, as
evidenced by the fact that he (co-)authored no less than 14 of the 37 preprints.
As a kind of satellite meeting for the Mittag-Leffler programme, a special session on
discrete probability was organized at the 25th Nordic and 1st British-Nordic Congress of
Mathematicians in Oslo in June 2009.
Organizing committee:
Sven Erick Alm, Uppsala,
Olle Häggström, Chalmers,
Svante Janson, Uppsala,
Kurt Johansson, KTH,
Jeff Steif, Chalmers.
On behalf of the organizing committee,
Sven Erick Alm
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Discrete Probability
Participants 2009 spring
Name
Alm, Sven Erick
Austrin, Per
Barbour, Andrew
Beffara, Vincent
Bender, Martin
Berg, van den, Jacob
University
Uppsala University
KTH
Universität Zürich
UMPA-ENS Lyon
University of Leuven
CWI
City
Uppsala
Stockholm
Zürich
Lyon
Leuven
Amsterdam
Arrival
15 Jan
15 Jan
16 May
15 Jan
11 May
31 Mar
2 Jun
Departure
15 Jun
15 Jun
13 Jun
8 Feb
31 May
29 Apr
12 Jun
Jerusalem
1 Feb
27 Feb
Cambridge
Cambridge
Stockholm
Göteborg
Amsterdam
Stockholm
Montreal
Västerås
Bonn
Baltimore
Lyon
Münster
Paris
15 Jun
8 Apr
20 May
15 Jun
14 Mar
15 Jun
29 May
8 May
27 Mar
9 Jun
8 Apr
26 Mar
15 Mar
23 May
15 Jun
15 Mar
16 Jun
14 Apr
22 Feb
15 Jun
Björnberg, Jakob
Bollobas, Bela
Britton, Tom
Broman, Erik
Camia, Federico
Deijfen, Maria
Devroye, Luc
Eriksson, Kimmo
Ferrari, Patrik
Fill, Jim
Fribergh, Alexander
Gantert, Nina
Garban, Christophe
Einstein Institute of
Mathematics
Statistical Laboratory
University of Cambridge
Stockholm University
Chalmers
Vrije Universiteit
Stockholm University
McGill University
Mälardalens högskola
University of Bonn
Johns Hopkins University
Université Lyon 1
University of Münster
Universite' Paris Sud
Guttmann, Tony
Hammond, Alan
University of Melbourne
ENS
Victoria
Paris
Hegarty, Peter
Heydenreich, Markus
Hoffman, Chris
Hofstad, van der,
Remco
Hollander, den, Frank
Holmgren, Cecilia
Holroyd, Alexander
Holst, Lars
Hwang, Hsien-Kuei
Häggström, Olle
Janson, Svante
Johansson A., Anders
Johansson, Fredrik
Johansson K., Kurt
Chalmers
Vrije Universiteit
University of Washington
Eindhoven University of
Technology
Leiden University
Uppsala UniversityU
University of British Columbia
KTH
Academia Sinica
Chalmers
Uppsala University
Högskolan i Gävle
KTH
KTH
Göteborg
Amsterdan
Seattle
15 Jan
6 Apr
14 Apr
15 Jan
16 Feb
15 Jan
10 May
14 Apr
1 Mar
17 May
15 Jan
2 Mar
15 Jan
10 May
15 May
6 Feb
18 May
16 Mar
25 Jan
16 May
Eindhoven
15 Jan
29 Jan
Leiden
Uppsala
Vancouver
Stockholm
Taipei
Göteborg
Uppsala
Gävle
Stockholm
Stockholm
1 Feb
15 Jan
9 Feb
15 Jan
27 Jan
2 Mar
15 Jan
3 Mar
30 Jan
15 Jan
27 Feb
15 Jun
16 Apr
15 Jun
14 Feb
5 Jun
11 Jun
30 Apr
15 Jun
15 Jun
Berger, Noam
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Jonasson, Johan
Jones, Liza
Kahn, Jeff
Kalai, Gil
Kang, Mihyun
Karonski, Michal
Kesten, Harry
Lagerås, Andreas
Limic, Vlada
Lindholm, Mathias
Linusson, Svante
Louchard, Guy
Luczak M, Malwina
Luczak T, Tomasz
Markström, Klas
Martin, James
Martin-Löf, Anders
McDiarmid, Colin
Metcalfe, Anthony
Mossel, Elchanan
Neininger, Ralph
Nordenstam, Eric
Norros, Ilkka
Pete, Gabor
Peterson, Jonathon
Renlund, Henrik
Riordan, Oliver
Rodl, Vojtech
Rucinski, Andrzej
Sanders, Tom
Seierstad, Taral
Seppäläinen, Timo
Sidoravicius, Vladas
Sorkin, Gregory
Spencer, Joel
Steif, Jeffrey
Söderberg, Bo
Thorisson, Hermann
Toth, Balint
Turova, Tatyana
Tykesson, Johan
Chalmers
University of Oxford
Rutgers University
Hebrew University
Technische Universität Berlin
Adam Mickiewicz University
6 Apr
15 Jan
15 May
1 Jun
1 Feb
19 Jan
26 May
Cornell University
Ithaca
20 Apr
Stockholm University
Stockholm
15 Jan
Université de Provence
Marseille
1 Apr
3 Jun
Stockholm University
Stockholm
15 Jan
KTH
Stockholm
15 Jan
Université Libre de Bruxelles
Bruxelles
23 Feb
London School of Economics
London
23 Mar
Adam Mickiewicz University
Poznan
15 Jan
Umeå University
Umeå
2 Feb
St Hugh's College
Oxford
22 Feb
Stockholm University
Stockholm
15 Jan
University of Oxford
Oxford
29 Mar
University College Cork
Cork
15 Jan
University of California
Berkeley
24 May
J.W.Goethe-Universität
Frankfurt
16 Feb
25 May
KTH
Stockholm
15 Jan
VTT, Helsinki
Helsinki
15 Jan
Mcrosoft Research
Redmond
6 May
University of Wisconsin
Madison
14 Jan
Uppsala University
Uppsala
15 Jan
University of Oxford
Oxford
26 Mar
Emory University
Atlanta
1 Jun
Adam Mickiewicz University
Poznan
26 Jan
4 May
Christ's College
Cambridge
12 Jan
University of Oslo
Oslo
15 Jan
University of Wisconsin-Madison Madison
16 Feb
IMPA
Rio de Janeiro 20 Apr
Yorktown
IBM Research
2 May
Heights
New York University
New York
16 Mar
Chalmers
Göteborg
20 Jan
6 Apr
Lund University
Lund
15 Apr
University of Iceland
Reykjavik
26 May
Budapest University of
Budapest
26 Apr
Technology
24 May
University of Lund
Lund
15 Jan
Chalmers
Göteborg
15 Jan
8
Göteborg
Oxford
Piscataway
Jerusalem
Berlin
Poznan
30 Apr
15 Jun
15 Jun
15 Jun
28 Feb
11 Feb
15 Jun
14 May
15 Jun
30 Apr
14 Jun
15 Jun
15 Jun
27 Feb
17 Apr
31 Mar
07 May
25 Mar
15 Jun
26 Apr
15 Jun
6 Jun
28 Feb
4 Jun
15 Jun
12 Mar
5 Jun
22 Mar
15 Jun
22 Apr
15 Jun
20 Feb
15 Jun
15 Jun
15 Apr
12 Mar
13 May
13 May
20 Apr
28 Feb
5 Jun
15 May
4 Jun
9 May
12 Jun
15 Jun
15 Jun
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Vallier, Thomas
Volkov, Stanislav
Warfheimer, Marcus
Wierman, John
Wilson, David
Wästlund, Johan
Institut Mittag-Leffler
University of Bristol
Chalmers
Johns Hopkins University
Microsoft Corporation
Chalmers
Djursholm
Bristol
Gothenburg
Baltimore
Redmond
Göteborg
Zeitouni, Ofer
University of Minnesota
Minneapolis
9
16 Mar
27 Apr
3 Feb
15 Jan
1 Apr
15 Jan
9 Apr
4 May
15 Jun
22 May
10 Feb
15 Jun
5 May
15 Feb
31 May
12 May
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Discrete Probability
Seminars 2009 spring
Andrew Barbour, Universität Zürich
Quasi-stationary distributions
Gil Kalai, Hebrew University, Jerusalem
Noise sensitivity
Svante Janson, Uppsala University
Audience's choice
Listeners are Kurt Johansson, Andrzej Rucinski, Vlada Limic and
Jacob van den Berg. Photo: M. Wiberg
Balint Toth, Budapest University of Technology
Long time asymptotics of self-repelling random walks
Gabor Pete, University of Toronto
The scaling limits of dynamical and near-critical percolation, and the minimal
spanning tree
Elchanan Mossel, University of California, Berkeley
Quantitative social choice theory
Christopher Hoffman, University of Washington,Seattle
Topology of random simplicial complexes
Alan Sokal, University of New York
The multivariate Tutte polynomial for graphs and matroids
Jim Fill, Johns Hopkins University, Baltimore
The numbers of symbol comparisons used by Quickselect and by Quicksort
Tony Guttmann, University of Melbourne, Victoria
Lattice green functions and Calabi-Yau equations
Mathias Lindholm, Stockholm University
Dynamic random networks
Martin Bender, University of Leuven
Edge scaling limits for non-Hermitian random matrices
Thomas Vallier, Institut Mittag-Leffler, Djursholm
Spread of activation on G(n,p)
Gregory Sorkin, IBM Research, Yorktown Heights
Average-case analyses of Vickrey costs
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Stanislav Volkov, University of Bristol
Going through a passport control with wife, or sequential adsorption at extremes
Maria Deijfen, Stockholm University
Invariant random graphs with prescribed iid degrees
Kimmo Eriksson, Mälardalens Högskola, Västerås
Cultural evolution as a random walk on integer partitions
Harry Kesten, Cornell University, Ithaca
Random walk with occasionally modified transition probabilities
Ofer Zeitouni, University of Minnesota, Minneapolis
Some aspects of large deviations for RWRE
Per Austrin, KTH, Stockholm
Randomly supported independence
Svante Linusson and Sven Erick Alm, KTH, Stockholm and Uppsala University
Surprising (?) correlations in randomly oriented graphs
Vladas Sidoravicius, IMPA, Rio de Janeiro
Fixation in the activated random walk model
Tom Britton, Stockholm University
Random networks and epidemics
Cecilia Holmgren, Uppsala University
A weakly 1-stable limiting distribution for the number of random records and cuttings
in split trees
Bo Söderberg, Lund University
Random Feynman graphs
Vlada Limic, Université de Provence, Marseille
The Lambda-coalescent speed of coming down from infinity
Anders Martin-Löf, Stockholm University
Pfaff, Ising and statistical mechanics
Johan Jonasson, Chalmers, Gothenburg
The bottom-to-top shuffle and the overlapping cycles shuffle
Colin McDiarmid, University of Oxford
Random graphs with few disjoint cycles
Rob van den Berg, CWI, Amsterdam
Sharpness of percolation transitions in some dependent 2D models
David Wilson, Microsoft Corporation, Redmond
A sharp threshold for minimum bounded-depth and bounded-diameter spanning trees
and Steiner trees in random networks
Oliver Riordan, Oxford University
Random graphs, the cut metric and branching processes
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Johan Wästlund, Chalmers, Gothenburg
Cancelling $\infty - \infty$ with games on graphs
Kurt Johansson, KTH, Stockholm
Universality in random matrix theory
Anders Johansson, University of Gävle
Factors in random graphs and hypergraphs
Malwina Luczak, London School of Economics
Averaging over fast variables in the fluid limit for Markov chains
Lars Holst, KTH,Stockholm
On records
Joel Spencer, New York University
Finding Lovász's needle in an exponential haystack
Peter Hegarty, Chalmers, Gothenburg
Concentration of measure in additive number theory
Erik Broman, Chalmers, Gothenburg
(Some new and some old results in) fractal percolation
Olle Häggström, Chalmers, Gothenburg
Dependent percolation on the square lattice
Svante Janson, Uppsala University
Susceptibility of random graphs
John Wierman, Johns Hopkins University, Baltimore
Triangle-duality and exact bond percolation thresholds
Anthony Metcalfe, University College Cork
Structural and universality properties of Gelfand-Tsetlin patterns and their
generalizations
Jakob Björnberg, Statistical Laboratory, Cambridge
Stochastic geometry of the space-time Ising model
Eric Nordenstam, KTH, Stockholm
The shuffling algorithm and the Aztec diamond
Patrik Ferrari, Weierstrass Institute, Berlin
Limit processes in KPZ growth
Nina Gantert, University of Münster
Nearly optimal paths and survival in a killed branching random walk
Liza Jones, Oxford University
Infinite systems of non-colliding processes
James Martin, St Hugh's College, Oxford
Multiclass queues and interchangeability
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Timo Seppäläinen, University of Wisconsin-Madison
Fluctuation bounds for a class of zero range processes
Alan Hammond, ENS, Paris
Trapping of a biased random walk on a supercritical tree
Christophe Garban, Université Paris Sud
The Fourier spectrum of critical percolation
Federico Camia, Vrije Universiteit, Amsterdam
Ising Euclidean fields and cluster area measures
Ralph Neininger, J.W. Goethe-Universität, Frankfurt
Probabilistic analysis of "Quickselect" and the contraction method
Johan Tykesson, Chalmers, Gothenburg
Aspects of continuum percolation in hyperbolic space
Klas Markström, Umeå University
Random Cayley-like graphs
Alexander Holroyd, University of British Columbia, Vancouver
Poisson matching
Frank den Hollander, Leiden University
Intermittency on catalysts
Noam Berger, Einstein Institute of Mathematics, Jerusalem
Slowdown estimates for ballistic random walk in random environment
Mihyun Kang, Technische Universität, Berlin
An ice-type model for random graphs embeddable on a surface
Michal Karonski, Adam Mickiewicz University, Poznan
Vertex-coloring edge-weightings
Markus Heydenreich, Vrije Universiteit, Amsterdam
Percolation on high dimensional boxes and related questions
Alexander Fribergh, Université Lyon 1
Biased random walks on a Galton-Watson tree with leaves
Hsien-Kuei Hwang, Academia Sinica, Taipei
A new analytic approach to the variance asymptotics of random digital trees
Andrzej Rucinski, Adam Mickiewicz University, Poznan
Subhypergraph counts in random hypergraphs
Jonathon Peterson, University of Wisconsin, Madison
Quenched limits for one-dimensional, transient, RWRE
Taral Guldahl Seierstad, University of Oslo
The differential equation method and random graphs
Remco van der Hofstad, Eindhoven University of Technology
First passage percolation on random graphs
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Vincent Beffara, UMPA-ENS, Lyon
Isotropic embeddings of planar lattices
Tomasz Luczak, Adam Mickiewics University, Poznan
Chasing robbers on random graphs
Tatyana Turova, Lund University
Asymptotics for the size of the largest component scaled to "log n" in inhomogeneous
random graphs
Tom Sanders, Christ's College, Cambridge
Probabilistic methods in additive combinatorics: sets with random spectrum
Ilkka Norros, VTT, Helsinki
Power-law random graphs and routing problems
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Discrete Probability
Preprints 2009 spring
01 - Critical behavior in inhomogeneous random graphs - Remco van der Hofstad
02 - Poset limits and exchangeable random posets - Svante Janson
03 - Delange's Tauberian theorem and asymptotic normality of random ordered
factorizations of integers - Hsien-Kuei Hwang, Svante Janson
04 - A mean-field approach to some Internet-like random networks - Ilkka Norros
05 - The diameter behavior in the random graph process - Tomasz Luczak, Taral
Guldahl Seierstad
06 - A survey of dynamical percolation - Jeffrey Steif
07 - Asymptotic normality of statistics on permutation tableaux - Pawel Hitczenko,
Svante Janson
08 - Triangle-duality and equality of infinitely many bond percolation thresholds John Wierman, Robert Ziff
09 - Equality of bond percolation critical exponents for pairs of dual lattices Matthew Sedlock, John Wierman
10 - Random graph asymptotics on high-dimensional tori. II. Volume, diameter
and mixing time – Markus Heydenreich, Remco van der Hofstad
11 - Aperiodic non-isomorphic lattices with equivalent percolation and randomcluster models. - Klas Markström, John Wierman
12 - Probability asymptotics: notes on notation - Svante Janson
13 - Duality in inhomogeneous random graphs, and the cut metric - Svante Janson,
Oliver Riordan
14 - Large cliques in a power-law random graph - Svante Janson, Tomasz Luczak, Ilkka
Norros
15 - Susceptibility in inhomogeneous random graphs - Svante Janson, Oliver Riordan
16 - Current fluctuations of a system of one-dimensional random walks in random
environment - Jonathon Peterson, Timo Seppäläinen
17 - Upper tails for counting objects in randomly induced subhypergraphs and
rooted random graphs - Svante Janson, Andrzej Rucinski
18 - Dynamic random networks in dynamic populations - Tom Britton, Mathias
Lindholm
19 - Quasi-random graphs and graph limits - Svante Janson
20 - A note on correlations in randomly oriented graphs - Svante Linusson
21 - Long and short paths in uniform random recursive dags - Luc Devroye, Svante
Janson
22 - A counter-intuitive correlation in a random tournament - Sven Erick Alm, Svante
Linusson
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
23 - Correlations for paths in random orientations of G(n,p) - Sven Erick Alm, Svante
Linusson
24 - On the speed of biased random walk in translation invariant percolation Maria Deijfen, Olle Häggström
25 - Growing networks with preferential deletion and addition of edges - Maria
Deijfen, Mathias Lindholm
26 - Diffusion approximation for the components in critical inhomogeneous
random graphs of rank 1. - Tatyana Turova
27 - A functional combinatorial central limit theorem - Andrew Barbour, Svante
Janson
28 - On the number of perfect matchings in random lifts - Catherine Greenhill,
Svante Janson, Andrzej Rucinski
29 - Noise Correlation Bounds for Uniform Low Degree Functions - Per Austrin,
Elchanan Mossel
30 - Dirac-type conditions for hamiltonian paths and cycles in 3-uniform
hypergraphs - Vojtech Rödl, Andrzej Rucinski, Endre Szemeredi
31 - Threshold graph limits and random threshold graphs - Persi Diaconis, Susan
Holmes, Svante Janson
32 - On the speed of coming down from infinity for $\X$-coalescent processes Vlada Limic
33 - Finite-dimensional distributions for the size of the core in random graphs Taral Seierstad
34 - Stronger large deviation bounds for Wormald's differential equation method Taral Seierstad
35 - Perfect matchings and Hamilton cycles in hypergraphs with large degrees Klas Markström, Andrzej Rucinski
36 - Susceptibility of random graphs with given vertex degrees - Svante Janson
37 - On Coupling and Convergence in Density and in Distribution - Hermann
Thorisson
16
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Mathematical Logic: Set Theory and Model Theory
Report 2009 fall
We discuss some highlights of the semester program in the area of Set Theory. The
program was very successful with significant progress achieved on the principal problems
of the proposal. These problems included problems related to the metamathematics of the
Continuum Hypothesis and problems at the frontier of the Inner Model Program.
The participants; D. Aspero, P. Larson, and J. Moore obtained a very nice result solving a
decade old problem relating to the Continuum Hypothesis. The problem posed in 1999
concerned Π22-maximality and the Continuum Hypothesis. The question asks whether there
are two Π22-sentences each of which is Ω-consistent with the Continuum Hypothesis but
which jointly refute the Continuum Hypothesis. One motivation for the question was the
result of Woodin which showed that assuming there is a proper class of measurable Woodin
cardinals, then for the case of Σ22-sentences the answer is no. The other motivation was the
discovery of the Pmax-axiom and this was really the primary motivation.
Aspero-Larson-Moore answer this question for Π22-sentences proving that there is such a
pair of Π22-sentences. This result shows that the maximality property that characterizes the
Pmax-axiom cannot be generalized to the Continuum Hypothesis. The result also places
constraints on possible generalizations of the forcing axiom, Martin’s Maximum, to the
context of CH.
Inspired by this result, Woodin showed that any such counterexample in the context of
generic-◇ yields the nonexistence of inner models at the level of superstrong cardinals.
While the failure of inner model theory at this level seems by current intuition extremely
unlikely this result shows how a development in the technical theory of forcing could lead
to such an unexpected theorem. Alternatively this result shows that the intuition from inner
model theory is that Π22-maximality must be possible with generic- and this in turn
suggests new directions for the technical theory of forcing in the context of forcing notions
which do not add reals.
Another series of results obtained during the semester program concerned the focus
problem: the fine-structure theory for one supercompact cardinal. Results obtained prior to
the Mittag-Leffler program have identified the inner model problem for one supercompact
cardinal as the key problem in extending inner model theory beyond the level of
superstrong cardinals. The reason is that these results show that the generalization of
Gödel’s Axiom of Constructibility to the level of exactly one supercompact cardinal yields a
provably maximal version of this axiom. The existence of such an “ultimate” version of
Gödel’s inner model L would have truly profound consequences in Set Theory and the
foundations of Mathematics.
The generalizations of L to large cardinals are in the form of extender models. For large
cardinals at the level of superstrong and below, the extenders are short extenders. The
detailed theory of these models was worked out by Mitchell and Steel (both of whom were
participants in the fall program) over 15 years ago. The extension of this theory beyond the
level of superstrong cardinals requires the development of the theory of extender models
involving long extenders. It has been realized for some time that dealing with long
extenders creates serious technical problems. Results obtained during the fall program by
Woodin have made significant progress on this problem yielding for the first time a
17
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
definition of fine-structural extender models with long extenders and generalizing
significant elements of the Mitchell-Steel theory to the context of these new models. The
theory is still at a preliminary stage and certain aspects could change but many key
obstacles have been identified and overcome.
Quite a number of other results were obtained by the participants on a variety of topics in
Set Theory. A very nice result was obtained by the two participants, Ilijas Farah and
Saharon Shelah, and shows that in ZFC any countable model has either 1 or 22 0 ‫ א‬nonisomorphic ultrapowers associated
with nonprincipal ultrafilters on N.
The result also applies to separable
metric structures, such as C*algebras and II1 factors. Their results
have already been submitted for
publication. Farah also working with
participants, P. McKenney and E.
Schimmerling, proved that assuming
the forcing axiom PFA then for every
Hilbert space (even nonseparable),
the automorphisms of the associated
Ilijas Farah, Paul McKenney and Ernest Schimmerling discuss in the
Calkin algebra are all inner.
lecture room. Photo: M. Wiberg
In the area of constructive set theory and topos theory a group of people worked on AczelMyhill constructive set theory, CZF. Thomas Streicher together with Alex Simpson finished
work on a sheaf model for CZF refuting both the power set axiom and unbounded
separation. Extensions of CZF with axioms related to predicativity issues in formal
topology, especially set-presentation of covers, were investigated by Benno van den Berg,
Hajime Ishihara and Erik Palmgren. They studied in particular the set-generation scheme
(SGS) and the principle for non-deterministic inductive definitions (NID) and their relation to
relativized dependent choice and similar principles true in the standard type-theoretic
model of CZF.
Topos theory and category-theoretic formulations of set theory were related topics of
research. Van den Berg finalized a major paper with Ieke Moerdijk on sheaves in
predicative algebraic set theory. Palmgren finished a paper relating Lawvere's categorical
set theory and Bishop's informal theory of sets. Jaap van Oosten discovered that the
effective topos contains at least part of a so-called Quillen model structure, which makes it
possible to develop a homotopy theory in this topos. The appropriate notion of path is very
much connected to the so-called "discrete reflection": the left adjoint to the inclusion of the
discrete objects in the topos. It allows the discrete objects to be characterized as "having
no nontrivial paths", and therefore (internally) the discrete reflection of an object as the set
of its path components.
The graduate student-participant, Daisuke Ikegami, working with Woodin, obtained a likely
solution to the problem of the relationship between determinacy and Blackwell
determinacy at the level of real games. The main result is that the Axiom of Real
Determinacy and the Axiom of Real Blackwell Determinacy are equivalent (in the context of
the base theory ZF + DC). The details are still being checked but the proof looks quite
promising.
Magidor and Väänänen finalized the solution of an old open problem concerning strong
Löwenheim-Skolem properties and supercompact cardinals.
18
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
On the non-mathematical side a potluck party was organized every week and four special
20 person dinners were organized where the junior members could meet a senior member
(Shelah, Magidor, Todorcevic
and Woodin). These dinners
were preceded by an informal
question-and-answers session,
and ended with a concert by
the grand piano. Both the
junior members and the senior
mathematician in question
alike reported that the
arrangement was very
successful and beneficial.
Vadim Kulikov plays guitar. In the front Professor and Mrs Magidor.
Photo: J. Väänänen
Organizing committee
Dag Normann, University of Oslo
Erik Palmgren, University of Uppsala
Jouko Väänänen, University of Helsinki and University of Amsterdam
Hugh Woodin, University of California at Berkeley
On behalf of the organizing committee
Jouko Väänänen
and
Erik Palmgren
19
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Mathematical Logic: Set Theory and Model Theory
Participants 2009 fall
Name
Asperó, David
University
Universitat de Barcelona
City
Barcelona
Bagaria, Joan
Baldwin, John
Berg, van den, Benno
Cummings, James
Di Prisco, Carlos
Dobrinen, Natasha
Dzamonja, Mirna
Enayat, Ali
Engström, Fredrik
Farah, Ilias
Flaskova, Jana
Galliani, Pietro
Hedin, Anton
Hella, Lauri
Hyttinen, Tapani
Ikegami, Daisuke
Universitat de Barcelona
University of Illinois
TU Darmstadt
Carnegie Mellon University
IVIC
University of Denver
University of East Anglia
American University
University of Gothenburg
York University
University of West Bohemia
University of Amsterdam
Uppsala University
University of Tampere
University of Helsinki
Universiteit van Amsterdam
Japan Advanded Institute of
Science and Technology
Alfréd Rényi Institut of
Mathematics
University of Helsinki
Helsinki University
California Institute of
Technology
University of Helsinki
Universiteit van Amsterdam
University of Helsinki
Rheinische-Friedrich-WilhelmUniversität
University of Illinois
Ben Gurion University
University of Helsinki
University of Uppsala
The Graduate Center
Helsinki University
Miami University
Uppsala University
ICMAT (CSIC)
Uppsala University
University of Helsinki
Barcelona
Chicago
Darmstadt
Pittsburgh
Caracas
Ishihara, Hajime
Juhász, István
Kangas, Kaisa
Kankaanpää, Teppo
Kechris, Alexander
Kennedy, Juliette
Keskinen, Lauri
Kesälä, Meeri
Koepke , Peter
Koerwien, Martin
Kojman, Menachem
Kontinen, Juha
Koponen, Vera
Kossak, Roman
Kulikov, Vadim
Larson, Paul
Lindström, Ingrid
Lopez-Abad, Jordi
Loukanova, Roussanka
Luosto, Kerkko
20
Norwich
Washington
Göteborg
Toronto
Plzeń
Amsterdam
Uppsala
Tampere
Helsinki
Amsterdam
Arrival
5 Sep
1 Nov
1 Nov
3 Sep
15 Oct
15 Nov
30 Oct
24 Nov
31 Aug
31 Aug
1 Sep
1 Sep
2 Sep
13 Nov
15 Sep
20 Oct
5 Oct
4 Sep
Departure
20 Sep
14 Nov
29 Nov
30 Oct
15 Dec
16 Dec
29 Nov
15 Dec
28 Sep
1 Nov
13 Nov
30 Sep
16 Dec
30 Nov
15 Dec
15 Dec
30 Oct
15 Dec
Ishikawa
13 Nov
1 Dec
Budapest
31 Aug
30 Sep
Helsinki
Helsinki
26 Oct
5 Oct
1 Nov
15 Dec
Pasadena
1 Sep
30 Sep
Helsinki
Amsterdam
Helsinki
27 Aug
1 Sep
15 Oct
15 Dec
15 Dec
15 Nov
Bonn
1 Dec
14 Dec
Chicago
Be'er-Sheva
Helsinki
Uppsala
New York
Helsinki
Oxford, Ohio
Uppsala
Madrid
Uppsala
Helsinki
18 Oct
1 Sep
2 Nov
1 Sep
1 Sep
1 Sep
1 Sep
1 Sep
1 Dec
1 Sep
1 Sep
31 Oct
12 Sep
4 Dec
15 Dec
15 Dec
15 Dec
15 Oct
15 Dec
13 Dec
15 Dec
15 Dec
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Magidor, Menachem
Martin-Löf, Per
McKenney, Paul
Mildenberger, Heike
Mitchell, William
Moore, Justin
Normann, Dag
Oosten, van, Jaap
Palmgren, Erik
Sabok, Marcin
Schimmerling, Ernest
Schindler, Ralf
Schlicht, Philipp
Shelah, Saharon
Steel, John
Stoltenberg, Viggo
Streicher, Thomas
Todorcevic, Stevo
Tuomi, Lauri
Velickovic, Boban
Villaveces, Andrés
Vlitas, Dimitrios
Väänänen, Jouko
Walczak-Typke, Agatha
Wilander, Olov
Wohofsky, Wolfgang
Woodin, Hugh
Yang, Fan
Zambrano, Pedro
The Hebrew University
Stockholms universitet
Carnegie Mellon University
The Hebrew University
University of Florida
Cornell University
University of Oslo
University of Utrecht
Uppsala University
Wroclaw University
Carnegie Mellon University
Universität Münster
Friedrich-Wilhelms-Universität
Hebrew University
University of California
Uppsala University
Technische Universität
University of Toronto
University of Helsinki
Université Paris 7
Universidad Nacional de
Colombia
University of Toronto
University of Helsinki and
Amsterdam
University of Vienna
Uppsala University
Vienna University of Technology
University of California Berkeley
University of Helsinki
Universidad Nacional de
Colombia
21
Jerusalem
Stockholm
Pittsburgh
Jerusalem
Gainesville
Ithaca
Oslo
Utrecht
Uppsala
Wroclaw
Pittsburgh
Münster
Bonn
Jerusalem
Berkeley
Uppsala
Darmstadt
Toronto
Helsinki
Paris
1 Sep
1 Sep
1 Sep
15 Nov
12 Oct
1 Sep
5 Oct
30 Sep
1 Sep
1 Sep
1 Sep
14 Sep
31 Aug
1 Sep
1 Sep
5 Oct
20 Sep
1 Sep
21 Oct
3 Oct
15 Dec
15 Dec
30 Sep
15 Dec
15 Dec
30 Sep
9 Oct
14 Dec
15 Dec
15 Dec
30 Sep
5 Nov
16 Dec
30 Sep
30 Sep
31 Oct
9 Oct
15 Dec
31 Oct
31 Oct
Bogotá
1 Oct
15 Nov
Toronto
Helsinki and
Amsterdam
Vienna
Uppsala
Vienna
Berkeley
Helsinki
26 Nov
6 Dec
27 Aug
15 Dec
31 Aug
1 Oct
14 Sep
9 Sep
2 Nov
15
15
27
12
13
Bogotà
1 Oct
16 Oct
Dec
Dec
Sep
Dec
Nov
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Mathematical Logic: Set theory and model theory
Seminars 2009 fall
Stevo Todorcevic, University of Toronto
gave a series of 4 lectures with the title: A basis problem for compact spaces
Jouko Väänänen, Universitites of Helsinki and of Amsterdam
gave a series of 5 lectures with the title: Set theory and logic
Erik Palmgren, Uppsala University
Constructivist and structuralist foundations: Bishop's and Lawvere's theories of sets
Bill Mitchell, University of Florida, Gainesville
The covering lemma: 35 years, and a question
Heike Mildenberger, Universität Wien
Filters versus semifilters
James Cummings, Carnegie Mellon University, Pittsburgh
Recent uses of infinitary methods in finite combinatorics
Jean Larson, Gainesville, Florida
Scattered thoughts on infinite combinatorics
Hajime Ishihara, Japan Advanced Institute of Science and Technology, Ishikawa
A boundedness principle in constructive reverse mathematics
Vera Koponen, University of Uppsala
Asymptotic probabilities of extension axioms.
Kerkko Luosto, University of Helsinki
Combinatorics of quantifiers
Joan Bagaria, Universitat de Barcelona
Large cardinals and accessible categories
Philipp Schlicht, Friedrich-Wilhelm-Universität, Bonn
Descriptive set theory at uncountable cardinals
Lauri Hella, University of Tampere
Monadic sigma-1-1 and modal logic with quantified binary relations
Juha Kontinen, University of Helsinki
Regular representations of uniform TC0.
Agatha Walczak-Typke, University of Vienna
Constructibility of potentially isomorphic pairs vs classification in homogeneous
model theory.
22
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Carlos Di Prisco, IVIC, Caracas
Graphs defined by the shift operation
Ralf Schindler, Universität Münster
Woodin's axiom (*), bounded forcing axioms, and related issues. Part II
Daisuke Ikegami, Universiteit van Amsterdam
Blackwell determinacy
Meeri Kesälä, University of Helsinki
Finitary abstract elementary classes
Fredrik Engström, University of Gothenburg
Logical constants and invariance
Menachem Magidor, the Hebrew University, Jerusalem
The Lowenheim-Skolem-Tarski number of the Hartig-quantifier can be the first
inaccessible
Benno van den Berg, TU Darmstadt
An introduction to algebraic set theory
Tapani Hyttinen, University of Helsinki
Model theory and metric structures
Vadim Kulikov. University of Helsinki
Equivalence relations on a generalized Baire space
Boban Velickovic, Université Paris 7
Universal countable Borel equivalence relations
Andrés Villaveces, Universidad Nacional de Colombia, Bogota
Dependence outside first order contexts
Dag Normann, University of Oslo
The sequential functionals are far from being algebraic domains
Jaap van Oosten, University of Utrecht
Constructions of (order-) partial combinatory algebras
Hugh Woodin, University of California, Berkeley
Pi-2-2 -maximality and generic diamond
Ralf Schindler, Universität Münster
Woodin's axiom (*), bounded forcing axioms, and related issues.
Jana Flaskova, University of West Bohemia, Plzeń
Some ultrafilters on natural numbers
Thomas Streicher, Technische Universität Darmstadt
Sheaf models for CZF refuting power set and full separation
Roman Kossak, City University of New York
Classification problems in models of Peano arithmetic
23
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Marcin Sabok, Wroclaw University
Playing with idealized forcing
Paul Larson, Miami University, Ohio
Universally measurable sets in generic extensions
Justin Moore, Cornell University, Ithaca
CH and the combinatorics of the club filter
Saharon Shelah, Hebrew University and Rutgers University
An advance on the existence of completely separable MAD families
Ali Enayat, American University, Washington DC
Automorphisms of Models of Set Theory
Alexander Kechris, CALTECH, Pasadena
The complexity of classification problems in ergodic theory.
Istvan Juhasz, Hungarian Academy of Sciences, Budapest
On the convergence and character spectra of compact spaces
John Baldwin, University of Illinois, Chicago
Shelah´s Conjecture: The Universe is Wide or Deep
Ilijas Farah, York University, Toronto
Model theory of operator algebras (joint work with Bradd Hart and David Sherman)
24
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Mathematical Logic: Set theory and model theory
Preprints 2009 fall
01 - CH, a problem of Rolewicz and bidiscrete systems - Mirna Džamonja, István
Juhász
02 - Measurable chromatic and independence numbers for ergodic graphs and
group actions - Alexander S. Kechris, Clinton T. Conley
03 - A dichotomy for the number of ultrapowers - Ilijas Farah, Saharon Shelah
04 - Constructivist and Structuralist Foundations: Bishop's and Lawvere's
Theories of Sets - Erik Palmgren
05 - Woodin's axiom (*), bounded forcing axioms, and precipitous ideals on
$\omega_1$ - Ralf Schindler
06 - Aspects of Predicative Algebraic Set Theory III: Sheaves - Benno van den Berg,
Ieke Moerdijk
07 - An Improper Arithmetically Closed Borel Subalgebra of P(omega) mod FIN Ali Enayat, Saharon Shelah
08 - On cofinal submodels and first interstices - Roman Kossak
09 - The Stability Spectrum for Classes of Atomic models - John Baldwin, Saharon
Shelah
10 - Interpreting Groups and Fields in Simple, Finitary AECs - Tapani Hyttinen, Meeri
Kesälä
11 - Forcing properties of ideals of closed sets - Marcin Sabok, Jindrich Zapletal
12 - Amalgamation, Absoluteness, and Categoricity - John Baldwin
13 - Rapid ultrafilters and summable ideals - Jana Flaskova
14 - Tukey types of ultrafilters - Natasha Dobrinen, Stevo Todorcevic
15 - On Löwenheim-Skolem-Tarski numbers for extensions of first order logic Menachem Magidor, Jouko Väänänen
16 - Model Theoretic Perspectives on the Philosophy of Mathematics - John Baldwin
17 - Asymptotic probabilities of extension properties - Vera Koponen
18 - Generic Banach spaces and generic simplexes - Jordi Lopez-Abad, Stevo
Todorcevic
19 - Lascar types and Lascar automorphisms in Abstract Elementary Classes Tapani Hyttinen, Meeri Kesälä
20 - Countable Ideals Models for CZF - Alex Simpson, Thomas Streicher
21 - Martin's maximum and weak square - James Cummings, Menachem Magidor
22 - A Remark on Negation in Dependence Logic - Juha Kontinen, Jouko Väänänen
23 - Non-permutation invariant Borel quantifiers - Fredrik Engström, Philipp Schlicht
24 - A Notion of Homotopy for the Effective Topos - Jaap van Oosten
25 - Regular Representations of Uniform $TC^0$ - Lauri Hella, Juha Kontinen, Kerkko
Luosto
26 - $C^{(n)}$-Cardinals - Joan Bagaria
27 - Notions of Independence for Metric Abstract Elementary Classes – Andrés
Villaveces, Pedro Zambrano
28 - On Milliken-Taylor Ultrafilters - Heike Mildenberger
29 - Remarks on Gaps in Dense(Q)/nwd - Teppo Kankaanpää
30 - Potential Isomorphism of Elementary Substructures of a Homogeneous Model
- Agatha Walczak-Typke, Tapani Hyttinen, Sy-David Friedman
25
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
31 - A Hanf Number for Satuation and Omission - John Baldwin, Saharon Shelah
32 - Real Determinacy and Real Blackwell Determinacy - Daisuke Ikegami, W. Hugh
Woodin
33 - Around Superstability in Metric Abstract Elementary Classes: Limit Models
and r-Towers - Andrés Villaveces, Pedro Zambrano
34 - On Ajtai Hypothesis in different cardinalities - Lauri Keskinen
35 - The relation of rapid ultrafilters and Q-points to van der Waerden ideal - Jana
Flaskova
36 - Remarks on the relation between families of setoids and identity in type
theory - Erik Palmgren
37 - On the maximal resolvability of monotonically normal spaces - Istvan Juhasz,
Menachem Magidor
38 - On $\Pi_2$-maximality and the Continuum Hypothesis - David Asperó, Paul
Larson, Justin Tatch Moore
26
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Participants from the Nordic countries
Finland
Hella, Lauri, Tampere
Hyttinen, Tapani, Helsinki
Kangas, Kaisa, Helsinki
Kankaanpää, Teppo, Helsinki
Kennedy, Juliette, Helsinki
Kesälä, Meeri, Helsinki
Keskinen, Lauri, Helsinki
Kontinen, Juha, Helsinki
Kulikov, Vadim, Helsinki
Luosto, Kerkko, Helsinki
Norros, Ilkka, Helsinki
Tuomi, Lauri, Helsinki
Väänänen, Jouko, Helsinki & Amsterdam
Norway
Normann, Dag, Oslo
Seierstad, Taral, Oslo
Sweden
Lagerås, Andreas, Stockholm
Lindholm, Mattias, Stockholm
Lindström, Ingrid, Uppsala
Linusson, Svante, Stockholm
Markström, Klas, Umeå
Martin-Löf, Anders, Stockholm
Martin-Löf, Per, Stockholm
Nordenstam, Eric, Stockholm
Palmgren, Erik, Uppsala
Renlund, Henrik, Uppsala
Steif, Jeff, Göteborg
Stoltenberg,Viggo, Uppsala
Söderberg, Bo, Lund
Turova, Tatyana, Lund
Tykesson, Johan, Göteborg
Vallier, Thomas, Lund
Warfheimer, Marcus, Göteborg
Wilander, Olov, Uppsala
Wästlund, Johan, Göteborg
Alm, Sven Erick, Uppsala
Austrin, Per, Stockholm
Björnberg, Jakob, Stockholm
Britton, Tom, Stockholm
Broman, Erik, Göteborg
Deijfen, Maria, Stockholm
Engström, Fredrik, Göteborg
Eriksson, Kimmo, Västerås
Hedin, Anton, Uppsala
Hegarty, Peter, Göteborg
Holmgren, Cecilia, Uppsala
Holst, Lars, Stockholm
Häggström, Olle, Göteborg
Janson,Svante, Uppsala
Johansson, Anders, Gävle
Johansson, Fredrik, Stockholm
Johansson, Kurt, Stockholm
Jonasson, Johan, Göteborg
Koponen, Vera, Uppsala
27
Publications
Institut Mittag-Leffler publishes two research journals. Acta Mathematica was founded by
Gösta Mittag-Leffler in 1882, while Arkiv för matematik traces its roots back to a journal
founded in 1903 by the Royal Swedish Academy of Sciences.
Since January 1, 2006 Springer is handling printing, subscriptions and distribution of both
journals. Naturally, the Institute retains full ownership and full editorial control of the
journals. All back volumes of both journals have been digitized by Springer and are
available on the web for subscribers.
Acta Mathematica
2 volumes/year (4 issues, totally 600 pp)
During 2009 the issues 202:1-2 and 203:1-2 have appeared
with in total 11 articles.
The influx of manuscripts has been very good.
Printed version: 474 copies
Electronic version: 5 547 subscribers via consortia of universities all over the world. In this
way the journal is reached by 34 African, 1 119 American, 1 313 Australasian and
3 081 European departments and institutions at different universities.
Editorial Board:
Anders Björner, Editor-in-Chief, Institut Mittag-Leffler
Karsten Grove, Dept of Mathematics, University of Notre Dame, USA;
Jens Carsten Jantzen, University of Aarhus, Denmark;
Kurt Johansson, Dept of Mathematics, The Royal Institute of Technology, KTH, Stockholm,
Sweden;
Pekka Koskela, Dept of Mathematics and Statistics, University of Jyväskylä, Finland;
Kristian Seip, Dept of Mathematical Sciences, NTNU, Trondheim, Norway;
Johannes Sjöstrand, IMB, Université de Bourgogne, Dijon, France
Technical Editors:
Anders Björn, Dept of Mathematics, Linköping University, Sweden;
Federico Incitti, Dept of Mathematics, Sapienza University of Rome, Italy.
Editorial Assistant:
Margareta Wiberg Roland, Institut Mittag-Leffler
28
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Arkiv för matematik
1 volume/year (2 issues, totally 400 pp)
The issues 46:1-2 have appeared during 2009
with in total 19 articles.
The influx of manuscripts has been sufficient, but could
be better.
Printed version: 215 copies
Electronic version: 5 050 subscribers via consortia of
universities all over the world. In this way the journal is
reached by 34 African, 899 American, 1 047 Australasian and
3 070 European departments and institutions at different universities.
Editorial Board:
Anders Björner, Editor-in-Chief, Institut Mittag-Leffler
Ralf Fröberg, Dept of Mathematics, Stockholm University, Sweden;
Olle Häggström, Dept of Mathematical Sciences, Chalmers University of Technology,
Göteborg, Sweden – 2009-06-30
Ari Laptev, Dept of Mathematics, The Royal Institute of Technology, KTH, Stockholm,
Sweden;
Mikael Passare, Dept of Mathematics, Stockholm University, Sweden
Peter Sjögren, Dept of Mathematics, Göteborg University, Sweden;
Jeffrey Steif, Dept of Mathematical Sciences, Chalmers University of Technology, Göteborg,
Sweden 2009-07-01 –
Technical Editor:
Anders Björn, Dept of Mathematics, Linköping University, Sweden
Editorial Assistant:
Margareta Wiberg Roland, Institut Mittag-Leffler
29
INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
The board of Institut Mittag-Leffler 2009
Bo Berndtsson, Chalmers University of Technology, CTH, Göteborg
Anders Björner, Director, Institut Mittag-Leffler
Torsten Ekedahl, Stockholm University
Olle Häggström, Chalmers University of Technology, CTH, Göteborg
Bjørn Jahren, University of Oslo, Vice Chairman
Svante Janson, Uppsala University
Kurt Johansson, Royal Institute of Technology, KTH, Stockholm
Jan-Erik Roos, Stockholm University, Chairman
Mikael Rørdam, Copenhagen, 2009-07-01 –
Eero Saksman, University of Helsinki
Jan Philip Solovej, H.C. Ørsted Institute, Copenhagen, Vice Chairman, – 2009-06-30
Anders Szepessy, Royal Institute of Technology, KTH, Stockholm
Hermann Thorisson, University of Iceland, Reykjavik
Hans Wallin, Umeå University
Board meeting November 2009. From left standing: A. Szepessy, H. Wallin, Lisbeth Wallin and Gunnar
Öquist, The Royal Swedish Academy of Sciences, T. Ekedahl, B. Jahren, S. Janson, J.-E. Roos, O. Häggström,
E. Saksman. Sitting: H. Thorisson, J.-P. Solovej, K. Johansson and A. Björner. Photo: M. Wiberg Roland
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Administrative information 2009
Staff
Anders Björner
Federico Incitti
Alexander Koponen
Marie-Louise Koskull
Fawzi Mourou
Mikael Rågstedt
Margareta Wiberg Roland
Director, 60%
Technical editor, 50%
Computer technician, 80%
Administrator of the scientific program
Caretaker
Librarian
Head of administration and economy
Fawzi Mourou, Alexander Koponen, Marie-Louise Koskull, Margareta Wiberg Roland, Anders
Björner and Mikael Rågstedt. Photo: C. Ameln
Research program
During 2009 the Institute hosted 151 visiting researchers, who together spent 272.5 manmonths working at the Institute.
Library and historical archive
The library subscribes to several electronic journals and to around 110 print journals. In
addition, we receive some 70 journals in exchange for Acta Mathematica and Arkiv för
matematik.
Information and copies from the historical archive are frequently requested, including visits
by mathematical historians.
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INSTITUT MITTAG-LEFLER – A NORDIC INSTITUT FOR RESEARCH IN MATHEMATICS
Financial statement
(kSEK)
Result 2009
Result 2008
Income
Contributions from Nordic countries
1 067
787
Contribution from the Swedish Research Council
Grant Income
Other Income
1 100
1 260
592
1 105
1 029
737
Total External Income
Journals net
4 019
495
3 657
718
Profit available for distribution from the Endowment
Exceeded withdrawal from the Endowment
2 974
1 069
3 344
806
Total Income
8 558
8 525
Expenditure
Scientific Program - Grants
Offices and Lodging
Library
Administration
1 582
2 256
1 516
3 203
1 888
1 938
1 519
3 180
Total Costs
8 558
8 525
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