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 Events
UAlberta
Mon 24 Nov 2014, 3:00pm
CRG Geometry and Physics Seminar
ESB 4127 (host: UBC)
Modules of differentials for Lie algebras
ESB 4127 (host: UBC)
Mon 24 Nov 2014, 3:00pm-4:00pm

Abstract

In this talk, I will attempt to introduce/discuss modules of differentials for Lie algebras modelled after the corresponding notion for rings. This is relevant to the structure of certain infinite dimensional Lie algebras. This is joint work with Arturo Pianzola.
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Andrew Wathen
Mathematics Department, University of Oxford, UK
Tue 25 Nov 2014, 12:30pm
Scientific Computation and Applied & Industrial Mathematics
ESB 4133 (PIMS Lounge)
Preconditioning for models of coupled magma/mantle dynamics
ESB 4133 (PIMS Lounge)
Tue 25 Nov 2014, 12:30pm-1:30pm

Abstract


We will describe some recent work in the numerical simulation of problems of Geodynamics. The relevant partial differential equations share some of the features of the well-known Stokes equations, but there are significant differences. Our work has been to create rapid solvers for the large systems of equations arising from finite element approximation. We will briefly describe the relevant models and our preconditioned Krylov subspace iterative solvers which enable some of the first computations on these models.

This is joint work with Sander Rhebergen, Richard Katz, Garth Wells, John Rudge and Laura Alisic.

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Monica Musso
Pont. Cat. Univ. Chile
Tue 25 Nov 2014, 3:30pm
Diff. Geom, Math. Phys., PDE Seminar
ESB 2012
Nondegeneracy of nonradial nodal solutions to Yamabe problem
ESB 2012
Tue 25 Nov 2014, 3:30pm-4:30pm

Abstract

 We prove the existence of a sequence of nondegenerate, in the sense of Duyckaerts-Kenig-Merle, nodal nonradial solutions to the critical Yamabe problem or stationary energy-critical wave equation.
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Tyler Helmuth
Tue 25 Nov 2014, 4:00pm SPECIAL
One Time Event
Graduate Student Center, Room 203
Doctoral Exam
Graduate Student Center, Room 203
Tue 25 Nov 2014, 4:00pm-6:30pm

Details

Spin systems such as the Ising model are central topics in statistical mechanics and probability theory. In the late 1960s Symanzik made the important discovery that properties of spin systems could be expressed in terms of the behaviour of random walks. This thesis contributes to the understanding of these connections by developing and analyzing random walk representations of graphical models arising in statistical mechanics.
Concretely, the results of this thesis can be divided into two parts. The first part is a lace expansion analysis of a model called loop-weighted walk. Loop-weighted walk is a non-Markovian model of random walks that are discouraged (or encouraged), depending on the value of a parameter, from completing loops. The model arises naturally as a random walk representation of correlations in a statistical mechanics model called the cycle gas. A challenging aspect of this model is that it is not repulsive, meaning the weight of the future of a walk may either increase or decrease if the past is forgotten. Loop-weighted walk is the first finite range walk model with this property to be analyzed with lace expansion techniques.
The second part of this thesis is an essentially elementary derivation of a random walk representation for the partition function of the Ising model on any finite graph. Such representations have a long history for planar graphs. For non-planar graphs the additional ingredient needed is a way to compute the intersection numbers of curves on surfaces. The representations for non-planar graphs lead to random walk representations of spin-spin correlation functions that were previously unknown.
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Kseniya Garaschuk
UBC
Tue 25 Nov 2014, 4:00pm
Discrete Math Seminar
ESB 4127
Some aspects of rational triangle decompositions.
ESB 4127
Tue 25 Nov 2014, 4:00pm-5:00pm

Abstract

Given a simple graph $G$, a triangle decomposition of $G$ is a set of subgraphs isomorphic to $K_3$ whose edges partition the edge set of $G$. Further, a rational triangle decomposition of $G$ is a non-negative rational weighting of the copies of $K_3$ in $G$ such that the total weight on any edge of $G$ equals one. In this thesis, we will explore sufficient conditions for rational triangle decomposability. A famous conjecture in the area due to Nash-Williams states that any sufficiently large graph (satisfying some divisibility conditions) with minimum degree at least $3/4v$ is admits a triangle decomposition; the same conjecture stands for rational triangle decomposability (no divisibility conditions required). By perturbing and restricting the coverage matrix of a complete graph, we show that minimum degree of at least $22/23v$ is sufficient to guarantee that the given graph is rationally triangle decomposable. This density bound is a great improvement over the previously known results and is derived using estimates on the matrix norms and structures originating from association schemes.
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UAlberta
Wed 26 Nov 2014, 3:00pm
CRG Geometry and Physics Seminar
ESB 4127 (host: UAlberta)
TBA
ESB 4127 (host: UAlberta)
Wed 26 Nov 2014, 3:00pm-4:00pm

Abstract

 TBA
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Stefan Adams
Warwick University
Wed 26 Nov 2014, 3:10pm
Probability Seminar
ESB 2012
Phase Transitions in Continuum Delaunay Potts Models
ESB 2012
Wed 26 Nov 2014, 3:10pm-4:10pm

Abstract

We discuss recent results on phase transitions of  Delaunay Potts models in dimension two where the interaction depends on Delaunay edges respectively Delaunay triangles.

This work is an extension of the Lebowitz & Lieb soft-core continuum Potts model to geometrically dependent interaction systems. The main tool is a FK (Fortuin-Kasteleyn)  random cluster representation adapted to the Delaunay structure and percolation in the FK model.  If time permits we discuss the Voronoi-Ising model where the interaction is function of the length of the common boundary and its connection to variants of the RSW (Russo-Seymour-Welsh) theorem in continuum percolation. 

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MIT
Wed 26 Nov 2014, 3:15pm
Topology and related seminars
ESB 4133
The six operations of Grothendieck in equivariant motivic homotopy theory
ESB 4133
Wed 26 Nov 2014, 3:15pm-4:15pm

Abstract

The formalism of six operations encodes the functorial behavior of (co)homology theories. It was first introduced by Grothendieck for the l-adic cohomology of schemes, and was later developed in a variety of other geometric contexts: D-modules on schemes, spectra parametrized by topological spaces, motivic spectra parametrized by schemes, etc. Equivariant homotopy theory is also best understood as a formalism of six operations for topological stacks. In this talk I will discuss the basics and the significance of this formalism, and I will then describe an extension of motivic homotopy theory to algebraic stacks.
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Abdul Kara
Witwatersrand University
Wed 26 Nov 2014, 3:30pm
Symmetries and Differential Equations Seminar
MATH 125
Symmetry structures of manifolds Part II
MATH 125
Wed 26 Nov 2014, 3:30pm-4:30pm

Abstract


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Oxford University
Thu 27 Nov 2014, 3:30pm
Number Theory Seminar
room MATH 126
Auto-correlations of divisor functions in function fields
room MATH 126
Thu 27 Nov 2014, 3:30pm-4:30pm

Abstract

In this seminar I will discuss a function field analogue of a classical problem in analytic number theory, concerning the auto-correlations of divisor functions, in the limit of a large finite field.
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University of Oregon
Fri 28 Nov 2014, 2:00pm SPECIAL
Diff. Geom, Math. Phys., PDE Seminar
ESB 4133 (PIMS lounge)
Geometric flow on almost Hermitian manifolds
ESB 4133 (PIMS lounge)
Fri 28 Nov 2014, 2:00pm-3:00pm

Abstract

 

Note for Attendees

 Note unusual day and time.
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UBC
Fri 28 Nov 2014, 3:00pm
Department Colloquium
MATX 1100
Graduate Research Award lecture: Magnetized Target Fusion: Insights from Mathematical Modelling
MATX 1100
Fri 28 Nov 2014, 3:00pm-4:00pm

Abstract

Magnetized target fusion reactors are a modern design to for hydrogen fusion energy on earth. The design entails confining a plasma with a magnetic field and crushing it in an imploding shell of molten metal. Such a design has many unresolved questions in terms of its feasibility as a power source and the most important elements in making it efficient. In this talk, we will look into two of the approaches undertaken to explore these questions. Firstly, through a coordinate transformation and implementing a novel flux-limited, split-step, finite volume scheme for nonlinear coupled hyperbolic partial differential equations, we do a parameter sensitivity analysis for the design performance. Secondly, by a careful series of asymptotic arguments, we establish a leading order asymptotic expression for the plasma compression. This expression is qualitatively consistent with the numerical work, but it also gives new insights into how the device operates. We will conclude with a look into the viability of magnetized target fusion and its future work.

Note for Attendees

Refreshments will be served at 2:45pm in the Math Lounge area, MATH 125 before the colloquium.


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UBC
Mon 1 Dec 2014, 3:00pm
CRG Geometry and Physics Seminar
ESB 4127 (host: UBC)
The topological Fukaya category and mirror symmetry for toric Calabi-Yau threefolds
ESB 4127 (host: UBC)
Mon 1 Dec 2014, 3:00pm-4:00pm

Abstract

The Fukaya category of open symplectic manifolds is expected to have good local-to-global properties. Based on this idea several people have developed sheaf-theoretic models for the Fukaya category of punctured Riemann surfaces: the name topological Fukaya category appearing in the title refers to the (equivalent) constructions due to Dyckerhoff-Kapranov, Nadler and Sibilla-Treumann-Zaslow. In this talk I will introduce the topological Fukaya category and explain applications to Homological Mirror Symmetry for toric Calabi-Yau threefolds. This is work in progress joint with James Pascaleff.
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Case Western
Wed 3 Dec 2014, 3:00pm
CRG Geometry and Physics Seminar
ESB 4127 (host: UAlberta)
TBA
ESB 4127 (host: UAlberta)
Wed 3 Dec 2014, 3:00pm-4:00pm

Abstract

 TBA
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Case Western
Wed 3 Dec 2014, 3:00pm
One Time Event
ESB 4127 (host: UAlberta)
TBA
ESB 4127 (host: UAlberta)
Wed 3 Dec 2014, 3:00pm-4:00pm

Details

 
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Sat 10 Jan 2015, 9:00am SPECIAL
One Time Event
To Be Announced
Analysis - Qualifying Exams
To Be Announced
Sat 10 Jan 2015, 9:00am-12:00pm
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Sat 10 Jan 2015, 1:00pm SPECIAL
One Time Event
To Be Announced
Differential Equations - Qualifying Exams
To Be Announced
Sat 10 Jan 2015, 1:00pm-4:00pm
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Sat 10 Jan 2015, 1:00pm SPECIAL
One Time Event
To Be Announced Later
Algebra Qualifying Exams
To Be Announced Later
Sat 10 Jan 2015, 1:00pm-4:00pm
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Nicolaos Kapouleas
Brown University
Tue 13 Jan 2015, 3:30pm
Diff. Geom, Math. Phys., PDE Seminar
ESB 2012
TBA
ESB 2012
Tue 13 Jan 2015, 3:30pm-4:30pm

Abstract

 
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Caltech
Fri 30 Jan 2015, 3:00pm
Department Colloquium
ESB 2012 (PIMS) TBA (time and date to be confirmed)
PIMS-UBC distinguished colloquium
ESB 2012 (PIMS) TBA (time and date to be confirmed)
Fri 30 Jan 2015, 3:00pm-4:00pm

Abstract


Note for Attendees

Coffee, tea and cookies served at 2:30pm in the PIMS Lounge, ESB 4133.
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UBC
Mon 2 Mar 2015, 4:00pm
Discrete Math Seminar
TBA
TBA
TBA
Mon 2 Mar 2015, 4:00pm-5:00pm

Abstract


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UCLA
Thu 5 Mar 2015, 3:30pm
Number Theory Seminar
room MATH 126
TBA
room MATH 126
Thu 5 Mar 2015, 3:30pm-4:30pm

Abstract

 
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UCLA
Fri 6 Mar 2015, 3:00pm
Department Colloquium
MATX 1100
TBA
MATX 1100
Fri 6 Mar 2015, 3:00pm-4:00pm

Abstract


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Colorado State University
Tue 10 Mar 2015, 4:00pm
Discrete Math Seminar
TBA
TBA
TBA
Tue 10 Mar 2015, 4:00pm-5:00pm

Abstract


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Brown University
Fri 13 Mar 2015, 3:00pm
Department Colloquium
ESB 2012 (PIMS)
PIMS-UBC Distinguished Colloquium, TitleTBA
ESB 2012 (PIMS)
Fri 13 Mar 2015, 3:00pm-4:00pm

Abstract


Note for Attendees

Coffee, tea and cookies served at 2:30pm in the PIMS Lounge, ESB 4133.
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UBC
Fri 20 Mar 2015, 3:00pm
Department Colloquium
MATX 1100
Graduate Research Award Lecture
MATX 1100
Fri 20 Mar 2015, 3:00pm-4:00pm

Abstract


Note for Attendees

Refreshments will be served at 2:45pm in the Math Lounge area, MATH 125 before the colloquium.
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Yakov Sinai
Princeton University
Fri 23 Oct 2015, 3:00pm SPECIAL
Department Colloquium / PIMS Seminars and PDF Colloquiums
ESB2012
TBA-PIMS/UBC Distinguished Colloquium
ESB2012
Fri 23 Oct 2015, 3:00pm-4:00pm
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