Eventi e divulgazione

Seminari
Giu
15
Gio
Parity-odd terms in the trace anomaly of Weyl fermions: elusive or illusory? (Sebastian Franchino-Vinas, Helmholtz-Institut Dresden-Rossendorf) @ Aula 603 e online
Giu 15@2:00 pm–3:00 pm

Seminario di Fisica Teorica INFN/DIFI

There is an ongoing discussion regarding the presence of a parity-odd term in the trace anomaly of a quantum field theory consisting of a free Weyl fermion in curved spacetime. The term in question is proportional to the Pontryagin density, times an imaginary factor of dangerous astrophysical implications. In this talk, I will begin by recalling some generalities of (trace) anomalies. Afterwards, I will slowly get into the details, exposing the particularities that arise in the case of Weyl fermions. I will state the arguments provided by those who claim that the odd term does exist, as well as the replies by those of us who asseverate the opposite.

Per connettersi a zoom:
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271

Giu
21
Mer
Gluon scattering in AdS from supersymmetric localization (Pietro Ferrero – Simons Center) @ Aula 602 e online
Giu 21@2:00 pm–3:00 pm

Seminario di Fisica Teorica INFN/DIFI

I will discuss some of the recent progress made in the computation of holographic correlators describing the scattering of gluons in anti de Sitter space. I will focus in particular on a special AdS_5 model, arising from N D3 branes probing a D7 brane singularity, which is the holographic description of a certain 4d N=2 USp(2N) gauge theory with matter. The (mass-deformed) partition function of such gauge theory gives a non-perturbative integral constraint that the holographic correlators must satisfy, thus allowing to fix a number of coefficients that cannot be obtained from bootstrap considerations alone. Among our results: we obtain a finite coupling expression for the first higher-derivative corrections in terms of modular functions, we derive the first three orders in the small alpha’ expansion of the Veneziano amplitude in AdS_5xS^3 and we completely fix a one-loop ambiguity in the gluon amplitude without a reference to the effective action on the D7 branes, which is not known.

Per connettersi a zoom:
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271


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