0368.4622

Seminar on random walks on graphs

Fall 2009.

Lecturer: Amnon Ta-Shma

When and where:  Mondays, 11:10-13:00. Location Shenkar 114.

Grading: Based on participation in class and paper presentation.

Books:

Olle Häggström

Finite Markov Chains and Algorithmic Applications

Mark Jerrum

Lecture Notes. Counting, sampling and integrating: algorithms and complexity

Russ Bubley

Randomized Algorithms: Approximation, Generation and Counting

Oded Goldreich

Computational Complexity: A Conceptual Perspective

Alan Freeze

Notes on counting

Further links:

A polynomial-time approximation algorithm for the permanent of a matrix with non-negative entries.
M. Jerrum, A. Sinclair, and E. Vigoda

In Journal of the ACM, 51(4):671-697, 2004.
A preliminary version appears in
STOC 2001.
Fulkerson prize, 2006.
Download: PDF



V. Guruswami Rapidly Mixing Markov Chains: A Comparison of Techniques

O. Reingold, Undirected ST-Connectivity in Log-Space, STOC 2005.

Dorit Aharonov Class on Markov Chains in Theoretical Computer Science

Lectures:

Date

Speaker

Topic

Reference

 

(1)

19.10.09


אמנון תא-שמע

Introduction. Basic definitions. Simple examples. Overview of seminar.

 

 (2)

26.10.09


אמנון תא-שמע

Markov chains. The Markov chain convergence theorem (with a coupling proof). The coupling lemma. A random walk on the cube.

[HAG, 4-5]

[Freeze, 2.3]



(-)

2.11.09

לא התקיים שיעור בגלל עץ שנפל על מסילת הרכבת





(3)

9.11.09

מילה גנדלסמן

ppt-1 ppt-2

Sampling . Gibbs sampler. The hard-core model. Random q-coloring in degree d graphs.

Fast convergence of the Gibbs sampler, q>2d^2

[HAG, 6-8], [Jerrum Chapter 4 ]



(4)

16.11.09




עומר

ppt

Path coupling. Fast convergence of the Gibbs sampler, q>2d+1.

Linear extension of a partial order.

PPT-I PPT-II

[Freeze 2.4] [Jerrum Chapter 4 ] [Bubley, Inyrtmezzo: Path coupling],

[Bubley, 5.7]

(5)

23.11.09

דני לשם

ppt

Sampling the Ising model exactly, using the Prop-Wilson algorithm

[HAG, 10-11]



(-)

30.11.09






(6)

7.12.09

שי ורדי

ppt

Exact counting. #P (Facts)

Approximate counting q-col in BPP

General Approximate counting in BPP^NP

[Jerrum Chapter 2 ] [HAG, 9]

[Jerrum Chapter 3 ] [Gold, 6.2.2.2]

 

(8)

14.12.09

(9)

21.12.09

(10)

28.12.09



אילן בן-בסט

עמרי

ppt I

ppt II

General graphs

Bounding mixing time through spectral gap, conductance, path congestion.

- undirected graph

- Reversible MC

- general directed graphs. II

[Freeze, 2.1,2.2,2.3]

(11)

4.1.10

רועי כגן

ppt

Sampling and approximate counting for weighted matchings (the monomer-dimer model)

[Freeze, 3.1,3.2]



(12)

11.1.10



דני לב

Counting perfect matchings in bipartite graph. Permanent of matrices with non-negative values.

The overall structure. Thm 3.3.2

[Freeze, 3.3] [Jerrum Chapter 5 ]

(13)

18.1.10

רועי ורנר

ppt

Reingold's algorithm for undirected connectivity in Logspace



Derandomized random walks.




The case of directed graphs