Saturday May 2nd 2015, at Bay View Academy, Monterey CA
The 30th Bay Area Discrete Math Day (BAD Math Day) will take place at Bay View Academy in Monterey, CA on Saturday, May 2nd, 2015. All talks will be held in the MUR.
BAD Math Days are oneday meetings aimed at facilitating communication between researchers and graduate students of discrete mathematics around the San Francisco Bay Area. These days happen twice a year and strive to create an informal atmosphere to talk about discrete mathematics. The term "discrete mathematics" is chosen to include at least the following topics: Algebraic and Enumerative Combinatorics, Discrete Geometry, Graph Theory, Coding and Design Theory, Combinatorial Aspects of Computational Algebra and Geometry, Combinatorial Optimization, Probabilistic Combinatorics, Combinatorial Aspects of Statistics, and Combinatorics in Mathematical Physics.
Registration
Light breakfast, lunch and dinner will be provided if you register at the bottom of this page by April 22nd, 2015. Missed this deadline and still considering attending? Please send email to Ralucca Gera
All talks will he held in the MUR at Bay View Academy.
9:0010:00am  Welcome and refreshments  10:0010:30am  Mateusz Michalek, Berkeley
Title: Quantum jumps of
normal polytopes

Abstract:
Normal polytopes are
combinatorial objects corresponding to embedded normal projective toric
varieties. Various
aspects of these polytopes have been studied with tools and inspirations coming
from algebra, geometry and
combinatorics. In my talk I would like to present the poset structure on the
family of normal polytopes, that
turns out to have very interesting geometry. I will focus on recent results
from a joint work with Winfried Bruns
and Joseph Gubeladze providing maximal normal polytopes. I will also present
several challenging open problems
 10:4511:15am  Jenny Wilson, Stanford Title: Representation stability and classical Weyl groups
 Abstract: Over the
past several years Church, Ellenberg, Farb, and Nagpal developed a framework
for studying sequences of representations of the symmetric groups, using a
concept they call an FImodule. I will give an overview of this theory, and
describe how it generalizes to representations of the Weyl groups in type B/C
and D. This machinery enables us to deduce strong constraints on the pattern of
irreducible representations, the characters, and the growth rate of these
sequences from an elementary "finite generation" condition.
Applications include the diagonal coinvariant algebras associated to the
classical Weyl groups, and the cohomology of various families of groups and
spaces related to Artin's braid groups.
 11:3012:30pm 
Kevin McCurley, Google
On Problem Selection in Mathematics Research

Abstract: When I was a graduate student, I had the luck
to hear a lecture by Richard Hamming on how to manage a research career in
mathematics. It's now 35 years later, and I've been lucky to have a career
where I worked in academia, in government, and in industry. Each of these has
different value systems, but each of them provide good sources for problems to
work on. I'll draw on some examples during my career to illustrate what makes a
good problem to work on.  12:302:00pm  Lunch
 2:00 2:30pm  Nora Youngs, Harvey Mudd College
Title: Neural codes and
convexity  Abstract: Neurons in
the brain represent stimuli via neural codes  binary vectors which
represent firing patterns. One important problem confronted by the brain
is to infer properties of represented stimulus spaces using only the intrinsic
structure of neural codes. How does the brain do this? To address this
question we define the neural ring, an algebraic object that encodes the full
combinatorial data of a code. We show how it can be used to extract relevant
features, and to give signatures of the code's realizability by convex sets.  2:45 3:15pm  Apoorva Khare, Stanford
Critical exponents of graphs 
Abstract: We study the set of powers that preserve positive
semidefiniteness, when applied entrywise to matrices with structure of zeros
prescribed by a graph. This is part of a broad program to study entrywise
functions preserving positivity on distinguished submanifolds of the cone. In
our main result, we completely classify the powers preserving positivity with
respect to all chordal/decomposable graphs. Additionally, we introduce a new graph
invariant which we call the "critical exponent". Our results provide
natural connections between combinatorics and analysis by relating the discrete
sparsity structures of matrices to their spectral properties. The work also has
applications in the regularization of covariance/correlation matrices, where
entrywise powers are used to separate signal from noise, while minimally
modifying the entries of the original matrix. (Based on joint work with D.
Guillot and B. Rajaratnam, Stanford.)
 3:15 4:00pm  Coffee break  4:00 5:00pm  Jan Vondrak, IBM Yet Another
Algorithmic Local Lemma?  Abstract: Following Moser's discovery of an efficient algorithm for
applications of the Lovasz Local Lemma, there has been extensive research on
various extensions of this result. We prove a unifying algorithmic local lemma
in an abstract setting assuming a "resampling oracle" for each event.
We show that the existence of resampling oracles is equivalent to a positive
association property similar to the assumptions of the "lopsided local
lemma". In particular, efficient resampling oracles can be designed for
the known application scenarios of the lopsided local lemma (random
permutations, matchings, spanning trees). We present several new algorithmic
results in these scenarios.
(joint work with Nick Harvey) 


Directions and Parking
Directions to Bay View Academy, are best found by asking Google Maps to direct you to the 222 Casa Verde Way, Monterey, CA 93940. If you are driving, parking (which is free unless otherwise marked) is available in the main parking lot, as well as on the street.
Organizers and Sponsors
The BAD Math Committee:
 Federico Ardila, San Francisco State University
 Ralucca Gera, Naval Postgraduate School
 Elizabeth Gross, San Jose State University
 Angela Hicks, Stanford University
 Tim Hsu, San Jose State University
 Carol Meyers, Lawrence Livermore National Laboratory
 Rick Scott, Santa Clara University
 William Slofstra, University of California, Davis
 Ellen Veomett, Saint Mary's College of California
 Yan Zhang, University of California, Berkeley
The 30th Bay Area Discrete Mathematics Day is kindly sponsored by D.E. Shaw and Elsevier, and hosted at Bay View Academy.
BAD Math Day Registration
Registration is open till April 22nd, 2015. Light breakfast, lunch and dinner will be provided if you registered by April 22nd, 2015. Missed this deadline and still considering attending? Please send email to Ralucca Gera.



