What is... the ring of symmetric functions?

Dasha Poliakova will explain what the ring of symmetric functions is.

Abstract: My original intention was to speak about Witt vectors, but this is a long topic. So instead I will talk about the ring of symmetric functions in infinitely many variables, which comes in two incarnations – as a ring of certain series and as a sum of representation rings of symmetric groups. I will define several algebraic structures on this object. If time permits, I will explain how those structures allow for a rather concise definition of big Witt vectors.

"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.