Physics Department Current Events
Physics ColloquiumWednesday, December 4, 2013
04:00 PM to 05:00 PM, Marshak Science Building, MR418N
Tony M. Liss, PhDMartin & Michele Cohen Dean of Science
The City College of New York
"After the Higgs"
On July 4, 2012 the ATLAS and CMS collaborations at the Large Hadron Collider announced the discovery of a particle that behaves a lot like a Standard Model Higgs boson. Is particle physics now done? Is the Standard Model complete? Do we now know everything? It will not surprise you that the answers to these questions are no, maybe, and no. I will review the status of the Big Questions in particle physics in light of the July 4 discovery and other recent results, and what we've learned about this new particle since then that may help answer some of them.
Thursday, December 4, 2013
High Energy Seminar
02:30 PM to 03:30 PM, Marshak Science Building, MR329
Mathematics, Professor, St. Peter's College, University of Oxford, Oxford UK
"Ambitwistor-strings and the scattering equations"
Abstract: We show that string theories admit chiral infinite tension analogues in which only the massless parts of the spectrum survive. Geometrically they describe holomorphic maps to spaces of complex null geodesics, known as ambitwistor spaces. They have the standard critical space--time dimensions of string theory (26 in the bosonic case and 10 for the superstring). Quantization leads to the formulae for tree--level scattering amplitudes of massless particles found recently by Cachazo, He and Yuan. These representations localize the vertex operators to solutions of the same equations found by Gross and Mende to govern the behaviour of strings in the limit of high energy, fixed angle scattering. Here, localization to the scattering equations emerges naturally as a consequence of working on ambitwistor space. The worldsheet theory suggests a way to extend these amplitudes to spinor fields and to loop level. We argue that this family of string theories is a natural extension of the existing twistor string theories.
High Energy Seminar
Friday, December 6, 2013
02:00 PM to 03:00 PM, Marshak Science Building, MR329
"Numerical test of the gauge/gravity duality at
quantum gravity level"
The strongest version of Maldacena's gauge/gravity duality conjecture claims the equivalence between the 1/N correction to maximally supersymmetric gauge theory and quantum correction to superstring theory. We test this conjecture by studying the D0-brane quantum mechanics (one-dimensional maximally supersymmetric gauge theory) numerically. We confirm quantitative agreement which strongly support the correctness of the Maldacena's conjecture at quantum gravity level. Furthermore we observed a negative specific heat of the black hole in our simulation of the gauge theory, which means the evaporation of the black hole can be described by the gauge theory.
Tony M. Liss, Ph.D., Martin & Michele Cohen Dean of Science, The City College of New York
Lionel Mason, Mathematics, Professor, St. Peter's College, University of Oxford, Oxford UK