
THE
FIELDS INSTITUTE FOR RESEARCH IN MATHEMATICAL SCIENCES

PUBLIC
LECTURES 201314
Fields Institute, 222 College Street, Toronto
(map)




UPCOMING TALKS
Avner
Magen Memorial Lectures
June
6, 2014 at 11 a.m.
KONSTANTINOS
GEORGIOU, University of Waterloo
Liftandproject systems for combinatorial optimization
problems; More than a decade of fascinating positive and
negative results
A popular paradigm in approximation algorithms for intractable
combinatorial optimization problems is to first formulate
the problem at hand as an integer program and then relax
the integrality condition, giving rise to a tractable
optimization problem. At the same time, the relaxation
introduces discrepancy between the true optimum and the
optimal solution of the relaxation, which can be properly
quantified so as to correspond to the approximability
one can achieve for the combinatorial problem. In order
to cope with this discrepancy, a number of systematic
procedures, known as liftandproject systems, have been
introduced that effectively tighten the relaxations and
that enjoy appealing algorithmic properties.
Over the last decade, numerous positive and negative
results have been established for liftandproject systems
and for various intractable optimization problems. On
one hand, the best algorithms known for a series of optimization
problems are due to liftandproject systems. On the other
hand, there is evidence that the limitations of liftandproject
systems as tools in approximation algorithms indicate
the actual hardness for a number of intractable optimization
problems.
In this talk I will review the area of liftandproject
systems. After a selfcontained and high level introduction
to the systems, I will discuss a number of applications,
trying to distill the main ingredients of this algorithmic
tool. At the same time I will try to expose its weaknesses
along with the challenges that are involved in showing
positive and negative results. The exposition will be
based on numerous fascinating results of the last decade
or so..
Past Avner Magen Memorial
Lectures
June
6, 2013
Bernard Chazelle, Princeton University (Video
of the talk)
Why Algorithms Are Poised to Become the Language
of the Living World
May 25, 2012
Avi Wigderson,
Institute for Advanced Study
Randomness
July 11, 2011
Avner Magen Memorial Lecture Day
BenGurion University


PAST TALKS 201314

FieldsPerimeter
Africa Postdoctoral Fellowship Lecture
March 19, 2014 at 2 p.m.
DINE OUSMANE SAMARY,
University of AbomeyCalavi, Benin and The Perimeter Institute
Master equation of correlation functions for tensorial
group field theory (video
of the talk)
In this talk we provide the closed equations that satisfy
correlation functions of the rank 3 and 4 tensorial group
field theory. WardTakahashi identities and SchwingerDyson
equations are combined to establish a nonlinear integral
equation for the twopoint functions. In the 3D case the
solution of this equation is given perturbatively at second
order of the coupling constant. [arxiv 1401.2096 and forthcoming
work].
Information
about Dr. Samary


February
3, 2014 at 2 p.m.
STAN WAGON, Mathematics and Computer
Science, Macalester College, St Paul Minnesota
Some Shocking Results in Mathematics (video
of the talk)
Some results are so shocking that they defy belief. The
talk will present several cases, from very elementary
to very sophisticated, that illustrate this point. Examples
presented will include: a modern interpretation of Hilbert's
Hotel, Julia Robinson's surprising doctoral theorem about
the rationals, a working model of a square wheel bike
and a squarehole drill, and an impossible construction
using regular tetrahedra.


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