Department of Mathematics Virtual Commutative Algebra Seminar. Speaker: Saugata Basu, Purdue University, West Lafayette, IN, USA Date/Time: 10 February 2023, 6:30pm (joining time 6:20 pm IST) Gmeet link: meet.google.com/ujm-mmpg-ckq [1] Title: Homology of symmetric semi-algebraic sets Abstract: Studying the homology groups of semi-algebraic subsets of $\mathbb{R}^n$ and obtaining upper boundson the Betti numbers has been a classical topic in real algebraic geometry beginning with the work of Petrovskii and Oleinik, Thom, and Milnor. In this talk I will consider semi-algebraic subsets of $\mathbb{R}^n$ which are defined by symmetric polynomials and are thus stable under the standard action of the symmetric group $\mathfrak{S}_n$ on $\mathbb{R}^n$. The homology groups (with rational coefficients) of such sets thus acquire extra structure as $\mathfrak{S}_n$-modules leading to possible refinements on the classical bounds. I will also mention some connections with a homological stability conjecture. Joint work (separately) with Daniel Perrucci and Cordian Riener. For more information and links to previous seminars, visit the website of VCAS: https://sites.google.com/view/virtual-comm-algebra-seminar