## Past Events at the University of Calgary

### Past Events

- 11-Oct-07

Why things don't fall down - Art, geometry and engineering

Why do some geometric shapes hold together, while others are floppy and fall down? An eggshell and a convex dome are rigid, while polygons, with four or more sides of fixed length in the plane, flex. The geometric principles for convex shapes go b more››

Scientific Event

- 10-Oct-07

The geometry of rigid and non-rigid structures

Convex triangulated surfaces in three-space are rigid by Cauchy's Theorem. But what about non-convex surfaces? Some interesting recent examples of classes of non-convex surfaces have some convex-like properties, and yet are still rigid. On the oth more››

Scientific Event

- 4-Oct-07

Total Positivity and its Applications

A matrix is called totally positive (resp. totally nonnegative)if all of its minors are positive (resp. nonnegative). This important class of matrices grew out of three separate applications: Vibrating systems, interpolation, and statistics. Since more››

Scientific Event

- 4-Oct-07

Scaling, universality and spatio-temporal clustering in seismicity and rock fracture phenomena

In this talk, Dr. Davidsen will give an overview of new methods from nonlinear sciences and complex network theory to characterize temporal and spatio-temporal clustering of point processes with a particular focus on their application to seismicity a more››

Industrial Event

- 3-Sep-07

The Intuitive Geometry Day in Calgary is a one-day meeting immediately following and extending the Intuitive Geometry Workhsop (August 31-September 2, 2007) held at the Banff International Research Station. The Intuitive Geometry Day is entir more››

Scientific Event

- 23-Jul-07
- 28-Jul-07

http://nanotech.ucalgary.ca/dsfd2007/ more››

Scientific Event

- 4-May-07
- 6-May-07

Western Canadian Conference for Young Researchers in Mathematics

Dear Graduate Students, Welcome to our conference website! This conference provides graduate students with a forum to discuss their research. With funds from PIMS and the University of Calgary, we can provide you with accommodat more››

Scientific Event

- 19-Apr-07

Gauss Sums: Finding the Root of Unity

A Gauss sum over a finite field GF(q) is a sum of q algebraic numbers. It is often useful to evaluate Gauss sums explicitly, for instance, in coding theoretic or cryptographic applications. For small q, the evaluation of Gauss sums can be done nai more››

Scientific Event

- 18-Apr-07

Values and Ideals in Combinatorial Problems

The absolute value of complex numbers is surprisingly useful in the investigation of certain combinatorial problems. The connection often arises from imbedding finite cyclic groups into the complex numbers by sending the group elements to roots of more››

Scientific Event

- 9-Mar-07

Amoebas, Coamoebas, and Tropical Geometry

Given a triangle with side lengths 1, log x, log y and opposite interior angles π-u-v, u, v, the functional determinant ∂(x,y)/∂(u,v) is identically equal to 1. This amusing fact is a special ins more››

Scientific Event

- 7-Dec-06

Time-Frequency Analysis: From Wireless Communications to Abstract Harmonic Analysis

In the talk I will discuss the relation between problems in wireless communications and time-frequency analysis. I will explain the basic principle of OFDM (orthogonal frequency division multiplexing) and its formulation in time-frequency analysis more››

Scientific Event

- 1-Dec-06

Energy minimization can be thought of as a broad generalization of sphere packing. Yudin discovered that harmonic analysis can be applied to prove lower bounds for potential energy. This talk will explain these bounds and show how to use them to p more››

Scientific Event

- 30-Nov-06

Optimality of the Leech lattice

This talk will outline the proof that the Leech lattice is the unique densest lattice in R24. The proof combines linear programming bounds with special algebraic and geometric arguments. This is joint work with Abhinav Kumar. more››

Scientific Event

- 29-Nov-06

Sphere packing and harmonic analysis

Harmonic analysis is one of the fundamental tools in sphere packing, in the form of "linear programming bounds". This talk will give a survey of linear programming bounds and their applications, as well as a brief introduction to semidef more››

Scientific Event

- 17-Nov-06

Scientific Event

- 16-Nov-06

Distribution of volume on isotropic convex bodies

Scientific Event

- 6-Oct-06

Traditional mathematical proofs are written in a way to make them easily understood by mathematicians. Routine logical steps are omitted. An enormous amount of context is assumed on the part of the reader. Proofs, especially in topology and geomet more››

Scientific Event

- 4-Oct-06

Computer-assisted proofs in geometry

In recent years, computer-assisted proofs have become relatively common. For example, in 2002, W. Tucker published a proof of problem 14 (concerning strange attractors) on Smale's list of problems for the new century. Other recent computer-assiste more››

Scientific Event

- 2-Oct-06

Kepler's conjecture asserts that the densest possible arrangement of congruent balls in three dimensions is the familiar pyramid arrangement, which is used to stack oranges at the fruit stand. A 300-page proof of this theorem finally appeared in J more››

Scientific Event

- 28-Sep-06

The integral geometry of random sets

In various scientific fields from astro- and high energy physics to neuroimaging, researchers observe entire images or functions rather than single observations. The integral geometric properties, notably the Euler characteristic of the level/excu more››

Scientific Event