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Annual progress seminar Date: 24th August, 2023 Time: 10:00 AM -- 11:00 AM Venue: Room 215 Host: Manoj Keshari Speaker: Sai Krishna Title: An algebraic characterization of the affine three space in arbitrary characteristic Abstract: We give an algebraic characterization of the affine three space over an algebraically closed field of arbitrary characteristic. We will look at a possible application of this characterization to reformulate the question of whether certain ring is isomorphic to the polynomial ring in three variables over an algebraically closed field of positive characteristic.
Annual Progress Seminar Time: 02:00 PM -- 02:35 PM Host: Sourav Pal Speaker: Priyanka Aroda Title: Contractions and their dilations Abstract: A contraction is an operator on a Hilbert space which has norm atmost 1. We study Sz.-Nagy's dilation theorem which models contractions as a part of nicer operators on larger spaces. We also discuss a more direct and explicit construction of a unitary dilation of a contraction, which is due to Schaffer. We study an analogue to Sz.-Nagy's dilation theorem, due to Ando, for a pair of commuting contractions.
Topology and Related Topics Seminar
Thursday, 24 August 2023, 2.30 -3:45 pm
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Venue: Room 215
Host: Rekha Santhanam
Speaker: Soumya Deb Samanta
Affiliation: IIT Bombay
Title: An Introduction to Riemannian Manifolds
Abstract: In this talk, I will give a brief introduction to the different aspects of Riemannian geometry: Riemannian metrics, affine connections, covariant derivatives, geodesics, curvature, Jacobi fields, and variation formulas. This talk will serve as a prelude to my next talk which will involve some topological aspects of Riemannian Manifolds.
Analysis Seminar Time: 02:40 PM -- 03:30 PM Host: Sourav Pal Speaker: Saikat Roy Title: Applications of Birkhoff-James orthogonality and its connection with dilation Abstract: Birkhoff-James orthogonality is a generalized notion of orthogonality that extends the inner product orthogonality to the setting of Banach spaces. In this talk, we present some of its applications in geometry of Banach spaces and its relation with norming properties of some subspaces of Banach space. We also consider operator orthogonality and its connection with the unitary and isometric dilations. We study the case when unitary (isometric) dilations of two contractions preserve the orthogonality relation between the basic contractions.