Debapriya Ojha will give her 2nd APS as follows.
25 September, 2-3 pm, Ramanujan Hall
Title: Hilbert's 17th Problem
Abstract: We will see the general concept of orderings of arbitrary
fields. We then establish relations between sums of squares in a field
and orderings of the same field. Next, we try to enlarge an ordered
field by extending the order to the new elements. Finally, we will
discuss Hilbert's 17th problem about the representation of forms by sums
of squares and its solution by Emil Artin . As an application of this
theorem we get the "sign change criterion".
Google Meet joining info
Video call link: https://meet.google.com/tgz-psxc-riq