### Next week Igor Pak will give the 2018 Erdős Lectures (delayed from June)

Here is the poster

## Combinatorics — Erdos lecture: Igor Pak (UCLA) “Counting linear extensions”

### Monday December 10 11:00-13:00

### Location: IIAS Hall 130, Feldman building, Givat Ram

I will survey various known and recent results on counting the number of linear extensions of finite posets. I will emphasize the asymptotic and complexity aspects for special families, where the problem is especially elegant yet remains #P-complete.

## CS Theory — Erdős Lecture: Igor Pak (UCLA) “Counting Young tableaux”

### Wednesday, Dec. 12, 2018, 10:30am to 12:00pm

### Location: Rothberg (CS building) B-220

The number of standard Young tableaux of skew shape is a mesmerizing special case of the number of linear extensions of posets, that is important for applications in representation theory and algebraic geometry. In this case there is a determinant formula, but finding their asymptotics is a difficult challenge. I will survey some of the many beautiful result on the subject, explain some surprising product formulas, connections to Selberg integral, lozenge tilings and certain particle systems.

## Colloquium: Erdos lecture – Igor Pak (UCLA) “Counting integer points in polytopes”

### Thursday, Dec 13, 2018 2:30pm to 3:30pm

### Location: Manchester Building (Hall 2), Hebrew University Jerusalem

Given a convex polytope P, what is the number of integer points in P? This problem is of great interest in combinatorics and discrete geometry, with many important applications ranging from integer programming to statistics. From a computational point of view it is hopeless in any dimensions, as the knapsack problem is a special case. Perhaps surprisingly, in bounded dimension the problem becomes tractable. How far can one go? Can one count points in projections of P, finite intersections of such projections, etc.?