2020 Feb 25

Logic Seminar - Martin Hils

2:00pm to 4:00pm


Ross building - Room 63,
Martin Hils will speal about Classification of imaginaries in valued fields with automorphism.

Title: Classification of imaginaries in valued fields with automorphism

Abstract: The imaginaries in the theory ACVF of non-triviallally valued algebraically closed
valued fields are classified by the so-called 'geometric' sorts. This is a fundamental
result due to Haskell-Hrushovski-Macpherson. We show that the imaginaries in
henselian equicharacteristic 0 valued fields may be reduced, under rather general
2020 Mar 24

Matan Seidel (TAU) Random walks on circle packings

2:00pm to 3:00pm

Abstract: A circle packing is a canonical way of representing a planar graph. There is a deep connection between the geometry of the circle packing and the proababilistic property of recurrence/transience of the simple random walk on the underlying graph, as shown in the famous He-Schramm Theorem. The removal of one of the Theorem's assumptions - that of bounded degrees - can cause the theorem to fail. However, by using certain natural weights that arise from the circle packing for a weighted random walk, (at least) one of the directions of the He-Schramm Theorem remains true.
2020 Mar 26

POSTPONED! Be'eri Greenfeld (BIU): How do algebras grow?

12:00pm to 1:00pm


Seminar room 209, Manchester Building, Jerusalem, Israel.
How do algebras grow?

The question of `how do algebras grow?', or, which functions can be realized as growth functions of algebras (associative/Lie, or algebras having certain additional algebraic properties) is a major problem in the meeting point of several mathematical fields including algebra, combinatorics, symbolic dynamics and more.

2020 Jan 29

Logic Seminar - Yatir Halevi

9:45am to 11:45am


Ross building - Room 63
Yatir Halevi will speal about Coloring Stable Graphs.

Title: Coloring Stable Graphs

Abstract: Given a graph G=(V,E), a coloring of G in \kappa colors is a
map c:V\to \kappa in which adjacent vertices are colored in different
colors. The chromatic number of G is the smallest such \kappa.
We will briefly review some questions and conjectures on the chromatic
number of infinite graphs and will mainly concentrate on the strong
form of Taylor's conjecture: