Upcoming Theory Seminars*

September 9

Speaker: Boaz Keren-Zur, Ecole Polytechnique

Title: "The local Callan-Symanzik equation: structure and applications"

Abstract:

The local Callan-Symanzik equation describes the response of a quantum field theory to local scale transformations in the presence of background sources. The consistency conditions associated with this anomalous equation can be used to derive powerful constraints on RG flows. We will discuss various aspects of the equation and present new results regarding the structure of the anomaly. We then use the equation to write correlation functions of the trace of the energy-momentum tensor off-criticality.

September 30

Speaker: Sam Gralla, University of Maryland

Title: TBD

October 7

Speaker: Alexander Vikman, NYU

Title: "NEC-violation, Stability, Causality and UV-Completion"

Abstract: 

I will discuss generic properties of systems violating the Null Energy Condition (NEC).
In particular I  will show why the Hamiltonian of these systems should necessarily be unbounded from below. Further I will stress the role of the external matter for the theories which are able to violate NEC without ghosts and gradient instabilities.  In particular, on the example of Galilean Genesis, I will show that the presence of external matter changes otherwise completely subluminal cosmology into a background with superluminal propagation of small perturbations. Finally I will briefly discuss possible UV-completions in such scenarios.

October 14

Speaker: Guilherme L. Pimentel, Princeton

Title: TBD

October 21

Speaker: David Spergel, Princeton

Title: TBD

November 11

Speaker: Mark Trodden, UPENN

Title: TBD

November 18

Speaker: Leonardo Rastelli, Stony Brook University

Title: TBD

November 25

Speaker: Marco Peloso, University of Minnesota

Title: TBD

December 9

Speaker:  Roman Scoccimarro, NYU

Title: TBD