Set Theory & Analysis
Spectre of a set
Piotr Nowakowski
University of Lodz, Poland
Thursday, 9. March 2023 - 10:00 to 11:30
Let (X,+) be an Abelian group. Let A be a subset of X. We define the spectre of a set A as
S(A) := {x in X: for all y in A we have y+x in A or y-x in A}.
We will show some properties of the spectre of a set and its connections with centre of distance and achievement sets
of absolutely convergent series.
IM in konírna