Dear All
Here’s the announcement of the next seminar in Hatano lab.
I myself will give a talk on arrow of time.
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Date: 16 November 2022 (13:00-)
Place: Main seminar room (IIS Kashiwa, 3rd floor)
Speaker: Naomichi Hatano
Title: Arrow of time in quantum mechanics
Abstract:
Why does the time flow only in one particular direction?
This is a very big and fundamental question of physics,
called the problem of “the arrow of time.” There are
a few types of the arrow of time. The cosmological arrow
of time refers to the direction of time in our universe
as we see it. The psychological arrow of time refers to the
direction of time that we perceive.
The arrow of time that
I am going to discuss in the present talk is the dynamical
arrow of time, which refers to the following problem.
The fundamental equations of motion, namely the Newton
equation for classical mechanics and the Schroedinger
equation for quantum mechanics, are symmetric if we
flip the arrow of time. Nonetheless, we see the oscillation of
a pendulum always diminishes and an excited state always decays
into the ground state.
How can this inconsistency arise? There have been many
answers to it but most of them attribute the reason to the
limitation of our ability of measuring physical systems.
My collaborator Gonzalo Ordonez and I have reservations because it
almost sounds like the dynamical arrow of time could be flipped or
eliminated if we have more abilities!
We answer the question of the dynamical arrow of time
in the realm of quantum mechanics in the following way.
We succeeded in deriving a time-reversal symmetric
decomposition of the time evolution operator which
contains both decaying states and growing states symmetrically.
If we watch the time evolution starting from an initial condition,
we pick all the decaying states, whereas if we watch the time evolution
ending in a terminal condition, we pick all the growing states.
This shows that the arrow of time is generated by the difference
in the way we watch the time evolution.
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The seminar will be also on line (zoom):
トピック: Talk by Naomichi Hatano
時間: 2022年11月16日 01:00 PM 大阪、札幌、東京
Zoomミーティングに参加する
u-tokyo-ac-jp.zoom.us/j/83484765780?pwd=K0ZZcXJjRng4VjJPMnQxdEdkdXFYdz09
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羽田野直道
277-8574 千葉県柏市柏の葉5-1-5
東京大学生産技術研究所
Phone: 04-7136-6961
Internal: 66961,66977
Fax: 04-7136-6978
hatano-lab.iis.u-tokyo.ac.jp/hatano/index-j.html
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