| Tuesday 16 April 2024 | |
| Events for day: Wednesday 08 July 2020 |
| 15:30 - 17:00 Geometry and Topology Seminar Lorentzian geometry and cohomogeneity one actions School MATHEMATICS In this talk, we introduce, briefly, the basis of Lorentzian geometry and cohomogeneity one actions. We also, introduce the Einstein universe and consider an interesting cohomogeneity one action on $mathbb{Ein}^{1,2}$. A smooth manifold $M$ equipped with a metric tensor $ extbf{g}$ of signature $(1, n)$ is called a Lorentzian manifold. Precisely, the restriction of $ extbf{g}$ to the tangent space $T_pM$ is of the form $−x_1^2+x_2^2+cdots+x_n^2$. Let $G$ be a Lie group which acts on a smooth manifold. Then the orbit of $G$ at point $pin M$ is $G(p) := {gp : g in G}$. If $G$ acts on $M$ smoothly, then every orbit of $G$ is ... 15:30 - 17:30 Mathtematical Logic Weekly Seminar Interpolative Fusions School MATHEMATICS The new notion of interpolative fusions provides a unified framework for studying many examples of "generic constructions" in model theory. Some, like structures with generic predicates, or algebraically closed fields with several independent valuations, are explicitly interpolative fusions, while others, like structures with generic automorphisms, or fields with generic operators, are bi-interpretable with interpolative fusions. The idea is to take two expansions T and T' of a common reduct theory and study models of their union such that the T and T' structures interact "randomly" up to constrains imposed by the common reduct. If T and T' a ... |