Professor Lord Martin Rees
Cambridge, UK

Fri 1 Sep 2017, 7:30pm
SPECIAL
Hebb Main Lecture Theatre, UBC Campus

From Mars to the Multiverse

Hebb Main Lecture Theatre, UBC Campus
Fri 1 Sep 2017, 7:30pm9:00pm
Details
For those in Vancouver on the Labour Day weekend, we have a really spectacular public event, on Friday evening (1st September). Lord Rees, from Cambridge (UK) will give a public lecture on "Mars and the Multiverse"; the abstract is below. Rees, one of the 20th century's most important astrophysicists, has also written on many other topics. He is well known around the world as a public speaker, particularly on our place in the universe as we now understand it, how to reconcile the findings of astronomy with religion, and the future of the human race. The talk he will give at UBC will allow extensive audience participation and dialogue with him, with plenty of opportunity for questions and discussion with him. This promises to be a really exceptional event. The talk will be suitable for the general public, including high school students.
Abstract:
In the year 2017, unmanned spacecraft have visited all the planets of our Solar System, and even some of their moons, and extensively explored Mars.
Many thousands of planets have been found orbiting other stars  some of these planets even resembling our Earth. Looking further afield, observers have probed galaxies and the massive back holes at their centres, and checked models of their evolution by detecting them all the way back to their formation. Indeed we can trace pregalactic history back to a nanosecond after the 'Big Bang'. But the key features of our universe  its expansion rate, geometry and content  were established far earlier even than this, at a time that precision measurements are now trying to probe.
All these advances pose key questions: What does the longrange cosmic future hold? Should we be surprised at the emergence of life? Is physical reality even vaster than what we can see? Are there many 'big bangs' and many universes? In this illustrated talk I will address these questions.
For more details, go to
http://pitp.physics.ubc.ca/quant_lect/2017/Rees.html
More details on Martin Rees:
Prof Martin Rees (Baron Rees of Ludlow)
Martin Rees is one of the pioneers of modern astrophysics, and played a key role in our understanding of black holes. A Professor at Cambridge University, he has also been successively Astronomer Royal (UK), and President of the Royal Society (London). He is wellknown to the general public for his popular books and for his public lectures  the one he will give at UBC in the evening of Sept 1st is for the general public, from 16 years upwards.
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UBC

Mon 11 Sep 2017, 4:00pm
Algebraic Geometry Seminar
MATH 126

Dynamics on automorphism groups of compact Kähler manifolds

MATH 126
Mon 11 Sep 2017, 4:00pm5:00pm
Abstract
Given a compact Kähler manifold X and a biholomorphic selfmap g of X, the topological entropy of g plays an important role in the study of dynamical system (X, g). In this talk, I first talk about a generalization of a surface result, that is, a parabolic automorphism of a compact Kähler surface preserves an elliptic fibration, to hyperkähler manifolds. We give a criterion for the existence of equivariant fibrations on ‘certain’ hyperkähler manifolds from a dynamical viewpoint. Next, I will generalize a finiteness result for the nullentropy subset of a commutative automorphism group due to Dinh–Sibony (2004), to arbitrary virtually solvable groups G of maximal dynamical rank. This is based on joint work with T.C. Dinh, J. Keum, and D.Q. Zhang.
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Tue 12 Sep 2017, 4:00pm
Discrete Math Seminar
ESB 4127

DM Committee Meeting

ESB 4127
Tue 12 Sep 2017, 4:00pm5:00pm
Abstract
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Wed 13 Sep 2017, 2:45pm
SPECIAL
ESB 4133 (PIMS Lounge)

PIMS Afternoon Tea runs weekly until November 29, 2017

ESB 4133 (PIMS Lounge)
Wed 13 Sep 2017, 2:45pm3:15pm
Details
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U Chicago

Thu 14 Sep 2017, 4:00pm
Discrete Math Seminar
ESB 4127

Duality theory via FourierMotzkin elimination

ESB 4127
Thu 14 Sep 2017, 4:00pm5:00pm
Abstract
We explore how FourierMotzkin elimination, a standard tool in finite dimensional linear programming, can be used to understand the duality theory of more general optimization problems, including semiinfinite linear, convex and conic programming.
This is joint work with Amitabh Basu (Johns Hopkins) and Kipp Martin (University of Chicago).
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UC Davis

Mon 18 Sep 2017, 4:00pm
Algebraic Geometry Seminar
MATH 126

Knot invariants and Hilbert schemes

MATH 126
Mon 18 Sep 2017, 4:00pm5:00pm
Abstract
I will discuss some recent results and conjectures relating knot invariants (such as HOMFLYPT polynomial and KhovanovRozansky homology) to algebraic geometry of Hilbert schemes of points on the plane. All notions will be introduced in the talk, no preliminary knowledge is assumed. This is a joint work with Andrei Negut and Jacob Rasmussen.
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Department of Computer Science, UBC

Tue 19 Sep 2017, 12:30pm
Scientific Computation and Applied & Industrial Mathematics
ESB 4133 (PIMS Lounge)

Numerical Analysis in Visual Computing: not too little, not too much

ESB 4133 (PIMS Lounge)
Tue 19 Sep 2017, 12:30pm1:30pm
Abstract
Visual computing is a wide area that includes computer graphics and image processing, where the ``eyeballnorm'' rules.
I will briefly discuss two case studies involving numerical methods and analysis applied to this area. The first involves motion simulation and calibration of soft objects such as cloth, plants and skin. The governing elastodynamics PDE system, discretized in space already at the variational level using corotated FEM, leads to a large, expensive to assemble, dynamical system in time, where the damped motion may mask highly oscillatory stiffness. Geometric integration ideas are making their way into visual computing research these days in search for more quantitative computations.
The other case study involves some image processing problems where there is a premium for local approaches that do not necessarily use underlying PDEs. I will demonstrate and discuss.
The examples used are from several published or submitted papers.
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Technical University of Munich

Tue 19 Sep 2017, 3:00pm
SPECIAL
LSK 306

Overview of the Julia programming language: an 8 hour minicourse

LSK 306
Tue 19 Sep 2017, 3:00pm5:30pm
Details
Course description: The Julia programming language is designed to be a high level language for numerical computing, that is as fast as C or Fortran, despite employing a high level syntax. Since its first release in 2012 it has been continually improved and build a fast growing community around it.
The aim of this course is to give an overview of the key concepts of the Julia programming language as well as explain the advantages over other languages designed for numerical computing, as e.g. Matlab or R. Furthermore it demonstrates how readily available packages developed with Julia can be used to solve common problems occurring in numerical analysis, such as  linear systems of equations  non linear systems of equations  ordinary differential equations  linear programs. The course will also cover the basic tasks frequently encountered by numerical analysts: benchmarking, plotting and debugging. If time permits we will also explore possibilities for using Julia in deep learning applications.
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Tokyo Institute of Technology

Tue 19 Sep 2017, 3:30pm
Diff. Geom, Math. Phys., PDE Seminar
ESB 2012

On uniqueness for the harmonic map heat flow in supercritical dimensions

ESB 2012
Tue 19 Sep 2017, 3:30pm4:30pm
Abstract
We examine the question of uniqueness for the equivariant reduction of the harmonic map heat flow in the energy supercritical dimension. It is shown that, generically, singular data can give rise to two distinct solutions which are both stable, and satisfy the local energy inequality. We also discuss how uniqueness can be retrieved. This is a joint work with Pierre Germain and TejEddine Ghoul.
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University of Victoria

Wed 20 Sep 2017, 3:00pm
Probability Seminar
ESB 2012

A characterization of the GFF

ESB 2012
Wed 20 Sep 2017, 3:00pm4:00pm
Abstract
We characterize the GFF as the only random distribution which is conformally invariant and satisfies a domain Markov property. Joint work with Nathanael Berestycki and Ellen Powell.
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Technical University of Munich

Wed 20 Sep 2017, 3:00pm
SPECIAL
LSK 306

Overview of the Julia programming Language: an 8 hour minicourse Part II

LSK 306
Wed 20 Sep 2017, 3:00pm5:30pm
Details
Course description: The Julia programming language is designed to be a high level language for numerical computing, that is as fast as C or Fortran, despite employing a high level syntax. Since its first release in 2012 it has been continually improved and build a fast growing community around it.
The aim of this course is to give an overview of the key concepts of the Julia programming language as well as explain the advantages over other languages designed for numerical computing, as e.g. Matlab or R. Furthermore it demonstrates how readily available packages developed with Julia can be used to solve common problems occurring in numerical analysis, such as  linear systems of equations  non linear systems of equations  ordinary differential equations  linear programs. The course will also cover the basic tasks frequently encountered by numerical analysts: benchmarking, plotting and debugging. If time permits we will also explore possibilities for using Julia in deep learning applications.
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CINVESTAV

Wed 20 Sep 2017, 3:15pm
Topology and related seminars
ESB 4133 (PIMS Lounge)

Hopf invariants in the motion planning problem

ESB 4133 (PIMS Lounge)
Wed 20 Sep 2017, 3:15pm4:15pm
Abstract
Hopf invariants, a basic construction in homotopy theory, are closely related to Lusternik–Schnirelmann category which, in turn, can be defined as the sectional category of a certain evaluation map. In this talk I'll introduce the notion of Hopf invariants for general fibrations and exhibit a connection between the Hopf invariants for a product fibration and those for the factors. Applications will be drawn to the motion planning problem.
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Technical University of Munich

Thu 21 Sep 2017, 3:00pm
SPECIAL
LSK 306

Overview of the Julia programming language: an 8 hour minicourse Part III

LSK 306
Thu 21 Sep 2017, 3:00pm5:30pm
Details
Course description: The Julia programming language is designed to be a high level language for numerical computing, that is as fast as C or Fortran, despite employing a high level syntax. Since its first release in 2012 it has been continually improved and build a fast growing community around it.
The aim of this course is to give an overview of the key concepts of the Julia programming language as well as explain the advantages over other languages designed for numerical computing, as e.g. Matlab or R. Furthermore it demonstrates how readily available packages developed with Julia can be used to solve common problems occurring in numerical analysis, such as  linear systems of equations  non linear systems of equations  ordinary differential equations  linear programs. The course will also cover the basic tasks frequently encountered by numerical analysts: benchmarking, plotting and debugging. If time permits we will also explore possibilities for using Julia in deep learning applications.
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UBC Math

Fri 22 Sep 2017, 3:00pm
Department Colloquium
ESB 2012

Some directions in analysis and geometry of probability measures

ESB 2012
Fri 22 Sep 2017, 3:00pm4:00pm
Abstract
Probability measures are key objects in many scientific and engineering areas that deal with randomness, distributions, data sets, etc. When coupled with optimization, many interesting questions naturally arise. In this talk, I will explain a few of such questions from the point of view of optimal transport theory, which gives a natural and robust framework for studying probability measures. These involve among others, matching probability measures in an optimal way following certain rules (e.g martingale), as well as finding geometric averages between probability measures.
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UBC

Mon 25 Sep 2017, 4:00pm
Algebraic Geometry Seminar
MATH 126

A power structure over the Grothendieck ring of geometric dg categories

MATH 126
Mon 25 Sep 2017, 4:00pm5:00pm
Abstract
The notion of a power structure is closely related to that of a lambda ring. It is a powerful way to encode operations on certain generating functions. GuseinZade, Luengo, and MelleHernandez have defined a power structure over the Grothendieck ring of varieties. I will discuss an analog of this on a version of the Grothendieck ring of pretriangulated categories, whose elements represent enhancements of derived categories of coherent sheaves on varieties.
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USC

Tue 26 Sep 2017, 4:00pm
Discrete Math Seminar
ESB 4127

Combinatorial bases of polynomials

ESB 4127
Tue 26 Sep 2017, 4:00pm5:00pm
Abstract
We establish a poset structure on combinatorial bases of polynomials, defined by positive expansions. These bases include the wellstudied Schubert polynomials, Demazure characters and Demazure atoms, as well as the recentlyintroduced slide and quasikey bases. The product of a Schur polynomial and an element of a basis in the poset expands positively in that basis; in particular we give the first LittlewoodRichardson rule for the product of a Schur polynomial and a quasikey polynomial, extending the rule of Haglund, Luoto, Mason and van Willigenburg for quasiSchur polynomials. We also establish bijections connecting combinatorial models for these polynomials, including semiskyline fillings and quasikey tableaux.
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The University of Melbourne

Wed 27 Sep 2017, 3:00pm
Discrete Math Seminar / Probability Seminar
ESB 2012

1324 patternavoiding permutations

ESB 2012
Wed 27 Sep 2017, 3:00pm4:00pm
Abstract
The field of patternavoiding permutations was introduced by Knuth in the 1960s as a way of characterising certain data structures.
Since then, it has grown into an important area in its own right. There are a number of classical problems, among which is the number of 1324avoiding
permutations. We will give some history, and then give details of a new algorithm we have developed for the generating function for this problem.
As a result we can count these up to length 50.
A new method of analysis we have developed, which can in some circumstances be an alternative to Monte Carlo analysis, reveals some interesting features.
In particular, we conjecture that the generating function is not Dfinite, and has asymptotics that include a stretchedexponential term.
(Joint work with Andrew Conway and Paul ZinnJustin).
The late, great Mark Kac often said that his seminars assumed zero knowledge but infinite wisdom.
This seminar only assumes zero knowledge and finite wisdom.
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UBC

Thu 28 Sep 2017, 12:30pm
Lunch Series on Teaching & Learning
MATH 126

Getting off on the wrong foot: early identification of “at risk” students in first term calculus

MATH 126
Thu 28 Sep 2017, 12:30pm1:30pm
Abstract
As an instructor, you have probably observed that a student's performance on the first midterm is strongly correlated with their final grade in the course, and that the lowest performing students on the midterm are often “at risk” of failing the course. In this lunch series I'll discuss two alternative ways of identifying at risk students, in the context of first term calculus. The first involves using data from the precalculus diagnostic test and the math attitude survey (MAPS). The second method involves mining data from the first webwork assignment. I'll discuss the variables identified as most important for predicting grades, and how the predictive model I have developed will be used as part of an intervention this semester in Math 180. Lastly, I'll discus some research I have done on “outlier” students whose final grade is far above what would be expected based on their first midterm score alone.
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University of Pennsylvania

Thu 28 Sep 2017, 3:30pm
Number Theory Seminar
Math 126

On free resolutions of Iwasawa modules

Math 126
Thu 28 Sep 2017, 3:30pm5:15pm
Abstract
The topic of the talk is motivated by certain questions on analytic side of (noncommutative) Iwasawa theory, namely the integrality properties of the padic Lfunction. Though we are motivated by these properties on the analytic side of Iwasawa theory, our work deals with the algebraic objects, called Iwasawa modules. We will discuss certain (nonprimitive) Iwasawa modules that have a free resolution of length one over appropriate Iwasawa algebras. If time permits, we will consider an application of this result involving an elliptic curve E over Q with a cyclic isogeny of degree p^2. This is joint work with Alexandra Nichifor.
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UBC Math

Fri 29 Sep 2017, 3:00pm
Department Colloquium
ESB 2012

Mathematics and Vantage College

ESB 2012
Fri 29 Sep 2017, 3:00pm4:00pm
Abstract
Vantage College is an academic program integrating content and language instruction for firstyear international students at UBC. Specially designed MATH 100 and MATH 101 courses have been offered to Vantage Science students since the program started in 2014.
In this presentation, I will give an overview of Vantage College, describe some innovations in firstyear Mathematics instruction that have been developed in the program, and make some recommendations about how the Mathematics Department might work with Vantage College in the coming years.
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Note for Attendees
Future Dates/Times of this ongoing minicourse: Wednesday, Sep 20, 3:005:30pm, Thursday, Sep 21 3:005:30pm.