APSPS/統計数学セミナー 12/17

[Yuta Koike]

IBISMLの皆様

東京大学の小池です。

12月のAsia-Pacific Seminar in Probability and Statistics (APSPS)の告知です。

Date: 17 December (Wed), 2025
Time: 14:00 (Japan)
Speaker: Stephen Muirhead
Title: Non-coincidence of critical points for directed polymers on
percolation clusters
Abstract: We consider the model of a directed polymer in a random
environment with independent and identically distributed space-time
disorder, in which the underlying random walk is defined on a typical
realization of an infinite cluster of supercritical Bernoulli bond
percolation in dimensions d ≥ 3. Generically, directed polymer models
defined via random walks on locally finite, connected graphs undergo a
phase transition between a strong disorder phase (at low temperatures)
and a weak disorder phase (at high temperatures), which can be
characterized by the decay (or lack thereof) of the normalized
partition function of the model as the polymer length increases. We
show that even though on any realization of the percolation cluster
the polymer is in a strong disorder phase, there is a regime in which
the decay rate is sub-exponential. This is in contrast to the
"sharpness" of the model on the full lattice in d ≥ 3 recently
established by Junk and Lacoin, namely the fact that on the full
lattice, the decay of normalized partition function to zero in the
strong disorder regime happens exponentially fast.

This talk is based on joint work with Francesca Cottini (Laboratoire
de Probabilités, Statistique et Modélisation, Sorbonne Université).

https://sites.google.com/view/apsps/home


東京大学からは、統計数学セミナーを通して、Zoomで配信します。
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統計数学セミナーオーガナイザー
吉田 朋広(東大数理)，増田 弘毅 (東大数理)，荻原 哲平(東大情報理工), 小池 祐太(東大数理)
Nakahiro Yoshida (University of Tokyo), Hiroki Masuda (University of
Tokyo), Teppei Ogihara (University of
Tokyo), Yuta Koike (University of Tokyo)
Email:  ogi...@mist.i.u-tokyo.ac.jp
Web:  http://www.ms.u-tokyo.ac.jp/seminar/probstat/future.html





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Asia-Pacific Seminar in Probability and Statistics


The seminar is created as a permanent forum for good research in the
field. It is our way to counterbalance the restrictions imposed on us
by the pandemic and to still promote scientific exchange and
cooperation. It will run using Zoom.

Topics include probabilistic models for natural phenomena, stochastic
processes and statistical inference, statistical problems in
high-dimensional spaces, asymptotic methods, statistical theory of
diversity. At the same time, there are no restrictions on other topics
of the seminar presentations.

The emphasis is on novelty, but even more so, on beauty, and clarity.
Where possible, heuristic arguments are preferred to presentation of
technical details.  Speakers are encouraged to discuss meaningful
applications and open problems.  Good reviews are welcome.
Presentations should be accessible to good postgraduate students in
probability and mathematical statistics.

The Board of the Seminar consists of

Anirvan Chakraborty (IISER, Kolkata)
Sanjay Chaudhuri (Univ. Nebraska-Lincoln)
Feng Chen (UNSW, Sydney)
Jie Yen Fan (Monash U, Melbourne)
Jesse Goodman (U Auckland)
Martin Hazelton (U Otago, Dunedin)
Mark Holmes (U Melbourne, currently at UBC, Vancouver)
Ajay Jasra (Chinese U of Hong-Kong, Shenzhen), Chair
Estate Khmaladze (VUW, Wellington)
Chenxu Li (Peking U)
Hiroki Masuda (U Tokyo)
Stephen Muirhead (U Melbourne)
Soumendu Sundar Mukherjee (ISI, Kolkata)
Teppei Ogihara (U Tokyo), Deputy Chair
Spiro Penev (UNSW, Sydney)
Rahul Roy (ISI, Delhi)
Lijiang Yang (Tsinghua U, Beijing)
Nakahiro Yoshida (U Tokyo)



The Board is responsible for the programme. All of us will be happy to
discuss details with potential speakers. Please, e-mail us if you
would like to contribute -- addresses readily obtainable on the web.

We plan to run seminars on Wednesdays, once a month. Time will vary in
between UTC+10 - UTC+12 (India) and UTC+17 - UTC+20 (New Zealand).
Specific dates will be given on the web-page
                                https://sites.google.com/view/apsps/home

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