##### Colloquia Spring 2019

**19-01-28 in Pascal**

Jonathan Lenells (KTH)

Jonathan Lenells (KTH)

*Long-time asymptotics for nonlinear integrable PDEs*

**19-02-25 in Pascal**

Søren Fournais (Århus)

Søren Fournais (Århus)

*Mathematics of the Bose Gas*

**19-04-04 in Euler**

Sylvie Paycha (Potsdam)

Sylvie Paycha (Potsdam)

*Are locality and renormalisation reconcilable?*

**19-04-15 in Pascal**

**Per Salberger (Chalmers/GU)**

*On Nevanlinna's theory of meromorphic functions*

**19-05-20 in Pascal**

**Johanna Pejlare (Chalmers/GU)**

*Calculating π in the 18th century*

Anders Gabriel Duhre (c.1680-1739), an important mathematician and mathematics educator in Sweden during the 18th century, contributed with two textbooks in mathematics, one in algebra and one in geometry. Among others, he treats infinitesimals based on Nieuwentijts’ theories from Analysis infinitorum and infinite series based on Wallis’ method of induction from Arithmetica infinitorum. Based on these results, Duhre develops an ingenious method to determine the area enclosed by curves by constructing a corresponding curve. He applies his method to the circle in order to find an expression of π as an infinite series. The series he finds is a modified version of the Gregory-Leibniz’ series. We consider in detail Duhre’s presentation in order to investigate the influence upon him as well as his influence on the Swedish mathematical society of his time.

##### Colloquia Autumn 2019

19-08-28 in Pascal

Elin Götmark (Chalmers/GU) *Mathematics for navigation*

What is the shortest travel distance between two cities as the crow flies? How can you determine your position on the Earth by means of the sun or stars? The answer relies on spherical trigonometry. This is old mathematics that first began to develop in Hellenistic times, but most of us do not encounter it in our university courses today. This talk will be accessible to undergraduate students.

19-09-23 in Euler

Richard Schoen (University of California, Irvine) *New perspectives on scalar curvature*

This will be a talk for a general audience explaining the dual role that the scalar curvature plays in differential geometry and in general relativity. Both subjects motivate questions about the geometric structure of spaces with scalar curvature bounded from below. We will describe some of these questions by analogy with similar questions for surfaces where the answers are largely known. In the physical case of dimension three we only have partial knowledge and many questions remain.

19-10-21 in Euler

Jeff Steif (Chalmers/GU) *Noise Sensitivity of Boolean Functions and Critical Percolation*

No background concerning percolation, Fourier analysis, hypercontractivity or geometric function theory will be assumed. [Slides]

19-11-18 in Pascal

Pär Kurlberg (KTH) *Repulsion in number theory and physics*

19-12-16 in Pascal

Aila Särkkä (Chalmers/GU)

*Sequential point processes - models for eye movements and sweat gland activation*