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Date: Fri, 9 May 2025 17:00:00 +0900
To: sg-l__AT__ml.yukawa.kyoto-u.ac.jp
Subject: [Sg-l:9371] 物性研理論インフォーマルセミナー[ハイブリッド] Pratik Nandy氏 5/16 13:30~
From: Tokiro Numasawa (Sg-l 経由) 

メーリングリストの皆様、

以下の要領で物性研理論インフォーマルセミナーをハイブリッドで開催します。
皆様のご参加を歓迎いたします。
(以下のリンク先のページで事前登録をしていただいた方に Zoom URLをお送りします。)

東京大学物性研究所
沼澤 宙朗

Dear colleagues

We are having a hybrid seminar at the Institute for Solid State Physics.
The details are as follows.
We welcome your attendance.
(We will send the Zoom link later if you register on the following page in
advance.)

Sincerely yours,
The University of Tokyo, Institute for Solid State Physics
Tokiro Numasawa

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Date: May 16 (Fri), 2025 13:30-
Place:  On Zoom and Lecture Room A615, ISSP (Hybrid)
Speaker:  Pratik Nandy
Affiliation: Yukawa Institute for Theoretical Physics, Riken
Title: A free probability approach to quantum chaos in random matrix
ensembles
Abstract:
 A quantum dynamical system can be described as an algebra of bounded
operators in a non-commutative probability space equipped with a time
evolution map. In free probability theory, quantum chaos is marked by “free
independence” between observables at early and late times, causing certain
statistical measures (cumulants) to vanish. Motivated by this, we study the
statistics of a time-evolved operator in the Rosenzweig-Porter (RP) random
matrix ensembles. The RP model displays a complex phase structure, namely
the ergodic, fractal, and localized regimes, featuring two phase
transitions. We show that the free probability approach is powerful enough
to distinguish these three phases. The numerical results in the ergodic
regime can be verified analytically using complex algebra tools such as the
Cauchy transform and Stieltjes inversion methods. This talk is based on an
ongoing work.


Please access the following URL for registration.
URL: https://forms.gle/6qb9BDQCebEYH5H49
Please also refer to the following URL:
https://www.issp.u-tokyo.ac.jp/maincontents/seminar/all2_en.html?pid=27049&ptype=seminar
Contact: Tokiro Numasawa (ext.63282)
e-mail: numasawa__AT__issp.u-tokyo.ac.jp