arXiv subjects

Maicol Di Giambattista

Publications and source records attributed to Maicol Di Giambattista.

3 recordsLinked to original sources

arXiv2024

Renormalization group flows and emergent symmetries

We discuss the following proposition: Renormalization Group flow of quantum theory with a biased symmetry exhibits a fixed hypersurface at which the symmetry is exact. Such emergent symmetries may have important phenomenological implications, including supersymmetric models, gauge theories, and massive gravity. Most interesting example is an emergent supersymmetry in non-abelian gauge theories with appropriate field content, in the IR limit i.e. strong coupling regime.

hep-th↗

arXiv2022

Classical and Quantum Dynamics of Gyroscopic Systems and Dark Energy

Gyroscopic systems in classical and quantum field theory are characterized by the presence of at least two scalar degrees of freedom and by terms that mix fields and their time derivatives in the quadratic Lagrangian. In Minkowski spacetime, they naturally appear in the presence of a coupling among fields with time-dependent vacuum expectation values and fields with space-dependent vacuum expectation values, breaking spontaneously Lorentz symmetry; this is the case for a supersolid. In a cosmological background a gyroscopic system can also arise from the time dependence of non-diagonal kinetic and mass matrices. We study the classical and quantum dynamics computing the correlation functions on the vacuum state that minimizes the energy. Two regions of stability in parameter space are found: in one region, dubbed normal, the Hamiltonian is positive defined, while in the second region, dubbed anomalous, it has no definite sign. Interestingly, in the anomalous region the 2-point correlation function exhibits a resonant behaviour in a certain region of parameter space. We show that dynamical dark energy models (with exact equation of state $w=-1$) can be realised as a gyroscopic system.

hep-th↗

arXiv2022

Quantum Corrections to the Stochastic Gravitational Wave Background

We study 1-loop corrections to the primordial stochastic background of gravitational waves produced during inflation. While in single-clock, at the leading order in slow-roll, quantum corrections keep the amplitude scale-free this is not the case when the pattern of symmetry breaking is different. In particular, when spatial diffeomorphisms are also broken during inflation as for solid inflation, a log-running in the external momentum is generated. We relate the appearance of a log-running to the spontaneous breaking of dilatation invariance. The running could be instrumental to distinguish single-clock from alternative models of inflation in future high sensitivity CMB polarisation and GWs experiments.

hep-th↗