Program v akademickém roce 2025/2026
27. 10. 2025, od 11:30
Anirban Sen, When is the Berezin range convex?
The seminar will take place in Professor Smital's Library (room no. 5)
20. 10. 2025, od 11:30
Petr Blaschke, Matrices with prescribed boundary of their numerical range and sinusoidal spirals.
The seminar will take place in Professor Smital's Library (room no. 5)
29. 9. 2025, od 11:30
Anirban Sen, A Gentle Tour of the Geometry of Numerical Range.
The seminar will take place in Professor Smital's Library (room no. 5)
Abstract:
The motivation for studying the numerical range comes from classical
quadratic forms, which were of central interest in the early days of
Hilbert space theory. Later, the chief interest shifted from quadratic
questions to operator theory and related notions such as numerical range.
The theories of numerical range and their applications appear in many
branches of sciences including operator theory, numerical analysis,
systems theory, quantum computing, and quantum information theory. The
extension of quadratic forms to the setting of linear operator on both
finite and infinite dimensional Hilbert spaces lead to the notion of
numerical range. In this talk, we discuss some basic geometric properties
of the numerical range and its relation with spectrum.
