What is... the spectrum of an unbounded operator?

Marie Fialová will explain what the spectrum of an unbounded operator is.

Abstract: Unbounded operators play significant role in physics. Our professor used to say, "Unbounded operator – it as if you said the domain in the same breath". Indeed, I would like to show a standard example of how the spectrum can be sensitive to the choice of a domain of an operator.

"What is...?" is an accessible and non-technical seminar where speakers explain in one (short) lecture some object or theorem that they think is interesting. There will be drinks and snacks during the talk. See the seminar website for more information.