On the 24th of January 2019, at 10:15 a.m.
Piotr
Waluk (KMMF)
will give a talk on
"
In
the beginning, there was chaos"
Abstract
The
Friedman-Lamaitre-Robertson-Walker
metric of a homogeneous and isotropic
universe is generally agreed upon today
as the cosmological model. However, the
question of why the observable universe
is so homogeneou and isotropic still
remains an open problem. To answer
it, one must try to analyze the possible
behaviour of space-time near a
cosmological singularity. One of the
attempts at such studies was the
Balinskii-Khalatnikov-Lifshitz
conjecture, which postulates that near
the singularity time derivatives of the
metric dominate heavily over spatial
derivaives and matter fields. This in
turn suggests consideration of spatially
homogeneous, but anisotropic space-time
models as good approximations.
I will begin my talk by discussing the
general structure of such space-times
and showing that their properties are
almost entirely determined by the Lie
algebra of their spatial Killing fields.
This allows them to be classified by the
Bianch classification of the
three-dimensional Lie algebras. Several
examples of particular physical interest
will be examined in detail - although
still relatively simple, some of these
solutions of the Einstein equations
display very untrivial properties, such
as modelling an isotropisation process
or even undergoing chaotic oscillations
when approaching the singularity.
The seminar takes place on Thursdays from 10:15 a.m. to
12:00 in the room 2.23 of the main building of the
Faculty of Physics (the 2nd floor), Pasteur Str. 5,
Warszawa.
Additional information can be found on the webpage http://oldwww.fuw.edu.pl/KMMF/sem.czw.przedp.html.
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