Graduate School in Physics and Astrophysics
-------------------------------------------
ANNUAL REPORT
-------------------------------------------
Fill with a text editor (without TAB or formatting)
Repeat fields for each course as necessary.
-------------------------------------------
name: Pier Vittorio Larocca
email: pier.vt@gmail.com
ciclo: XXIX
year completed (1,2 or 3): 3
supervisor: M. Frau, C. Maccaferri
-------------------------------------------
TEACHING ACTIVITIES
(only those done in the current year)
TUTORAGGIO:
METODI MATEMATICI E MECCANICA QUANTISTICA
Corso di laurea in Scienza e Tecnologia dei Materiali
ottobre – novembre 2016 (10 ore)
-------------------------------------------
SUMMER SCHOOLS, INTERNATIONAL SCHOOLS
(only those attended in the current year)
title: Spring School on Superstring Theory and Related Topics
place: Trieste
webpage: http://indico.ictp.it/event/7624/
days: 10 – 18 March 2015
talk or poster (Y/N): N
title: Valorizzare le competenze dei dottori di ricerca e accompagnarli nel mondo del lavoro
place: Torino - Rettorato
webpage: http://apresledoctorat.universite-lyon.fr/giornata-dedicata-alla-valorizzazione-delle-competenze-dei-dottori-di-ricerca-e-al-postdoc-torino-338332.kjsp?RH=ALD-ES
days: 4 October 2015
talk or poster (Y/N): N
---------------------------------------------------
Research activity/Publications in the current year
My research activity is on String Theory and String Field Theory.
I am studying the deformed Supersymmetric Yang-Mills gauge interaction from a string theoretical point of view. Gauge theories can be described by the dynamic of open strings attached on a stack of D-brane in a presence of closed string background.
In the 10-dimensional SuperString without closed string fluxes give us the famous N=4 SU(N) Super Yang Mills theory.
Our aim is to find the N=2* Super Yang Mills theory, which is a massive deformation of pure SYM. In order to obtain it we consider both RR and NSNS background closed string fluxes.
The interaction terms between fields living on D-branes can be found by computing the string amplitudes involving open and closed strings.
In the computation of the Yulawa coupling for both fermion and scalar fields, our method shows that amplitudes with two scalar fields are equivalent to ones with an auxiliary fields: this effect is due to a localization of the scalars.
From fermionic and bosonic Yukawa coupling we will be able to obtain mass terms for the theory. They will have the same structure in the closed string because of the supersymmetry.
Our result shows that it is not sufficient to consider these two background fluxes, but we need another closed string (the metric) in order to obtain the correct supersymmetric mass term.
In the open bosonic string field theory framework I studied perturbatively the solution of an exactly marginal defomration.
We assume the Ellwood conjecture: if I know a classical string field solution that lives on the BCFT where the string field theory is defined, the solution describes another BCFT with different boundary conditions. This means that the origninal string field theory defined on a certain D-brane, can describe any other D-brane system.
From the boundary CFT point of view a marginal deformation (depending on a BCFT parameter) changes its boundary conditions, and one can construct the boundary states (depending on that parameter).
The same is true in open SFT, but with a different parameter.
Comparing boundary states in the two theories, my result is the computation of the relation between these two parameters up to 5th order.
The computation involves divergent integrals, then they need a correct regularization to be well defined.
Our results show that this regularization, that avoid the tachyon singularity, leads to a different contribution between boundary CFT and String field theory. Hence, the relation we found is due to the different prescription for the integral regularization.