2019
Nov
05

# Events & Seminars

2019
Oct
28

# Combinatorics: Zlil Sela (HUJI) "Combinatorics and geometry in non-commutative algebraic geometry"

10:00am to 12:00pm

## Location:

CS building, room C-221

Speaker: Zlil Sela, HUJI

Title: Combinatorics and geometry in non-commutative algebraic geometry

Abstract:

Title: Combinatorics and geometry in non-commutative algebraic geometry

Abstract:

2020
Apr
30

2019
Oct
31

# Groups & Dynamics seminar - Vincent Guirardel (Universite de Rennes 1) "Measure Equivalence rigidity for Out(Fn)"

10:00am to 11:00am

## Location:

Ross 70

Abstract:

Measure equivalence of countable groups is a measure theoretic analogue

of quasi-isometry.

For example, any two lattices in the same Lie group are by definition

measure equivalent.

We prove that any countable group that is measure equivalent to Out(Fn)

is virtually isomorphic to Out(Fn). This is a joint work with Camille

Horbez.

Measure equivalence of countable groups is a measure theoretic analogue

of quasi-isometry.

For example, any two lattices in the same Lie group are by definition

measure equivalent.

We prove that any countable group that is measure equivalent to Out(Fn)

is virtually isomorphic to Out(Fn). This is a joint work with Camille

Horbez.

2019
Oct
29

# Zemer Kosloff, Finitary isomorphisms of Brownian motions

2:00pm to 3:00pm

Ornstein and Shields (Advances in Math., 10:143-146, 1973) proved that Brownian motion reflected on a bounded region is an infinite entropy Bernoulli flow and thus Ornstein theory yielded the existence of a measure-preserving isomorphism between any two such Brownian motions. For fixed h >0, we construct by elementary methods, isomorphisms with almost surely finite coding windows between Brownian motions reflected on the intervals [0, qh] for all positive rationals q. This is joint work with Terry Soo.

2019
Nov
19

# Tom Meyerovitch (BGU), Efficient finitary codings by Bernoulli processes

2:00pm to 3:00pm

Abstract:

Recently Uri Gabor refuted an old conjecture stating that any

finitary factor of an i.i.d process is finitarly isomorphic to an

i.i.d process. Complementing Gabor's result,

in this talk, which is based on work in progress with Yinon Spinka,

we will prove that any countable-valued process which is admits a

finitary a coding by some i.i.d process furthermore admits an

$\epsilon$-efficient finitary coding, for any positive $\epsilon$.

Here an ``$\epsilon$-efficient coding'' means that the entropy

Recently Uri Gabor refuted an old conjecture stating that any

finitary factor of an i.i.d process is finitarly isomorphic to an

i.i.d process. Complementing Gabor's result,

in this talk, which is based on work in progress with Yinon Spinka,

we will prove that any countable-valued process which is admits a

finitary a coding by some i.i.d process furthermore admits an

$\epsilon$-efficient finitary coding, for any positive $\epsilon$.

Here an ``$\epsilon$-efficient coding'' means that the entropy

2019
Nov
26

2019
Oct
31

# Basic Notions: Gil Kalai (HUJI) "Classical and quantum computation"

4:00pm to 5:15pm

## Location:

Ross 70

In the lecture I will describe basic notions of computational complexity:

Boolean functions, basic algorithmic tasks, Boolean circuits, P, NP, randomness, quantum circuits, noisy quantum circuits, bounded depth circuits, and more.

If time permits I will describe some (or more realistically one) mathematical challenge in the field and briefly

describe some examples (more realistically, one example) on how theory meets reality.

Boolean functions, basic algorithmic tasks, Boolean circuits, P, NP, randomness, quantum circuits, noisy quantum circuits, bounded depth circuits, and more.

If time permits I will describe some (or more realistically one) mathematical challenge in the field and briefly

describe some examples (more realistically, one example) on how theory meets reality.

2019
Dec
25

# Analysis Seminar: Adi Glucksam (Toronto)

12:00pm to 1:00pm

2019
Dec
03

# Uri Gabor

12:00pm to 1:00pm

2020
Jan
14

# Talk Cancelled.

2:00pm to 3:00pm

2019
Nov
12

# Uri Gabor (HUJI), On the failure of Ornstein's theory in the finitary category.

2:00pm to 3:00pm

Abstract: In this talk, I'll show the invalidity of finitary counterparts for three main theorems in classification theory: The preservation of being a Bernoulli shift through factors, Sinai's factor theorem, and the weak Pinsker property. This gives a negative answer to an old conjecture and to a recent open problem.

2019
Oct
29

2020
Jan
01

2019
Nov
06

# Analysis Seminar: Eyal Seelig (HUJI) "On the spacing of zeros of paraorthogonal polynomials for singular measures"

12:00pm to 1:00pm

## Location:

Ross 70

Title: On the spacing of zeros of paraorthogonal polynomials for singular measures

Abstract:

Abstract: