We evaluate the thermal expectation values in a free quantum field theory at global thermodynamic equilibrium with acceleration in Minkowski space- time. It is found that Unruh temperature TU = A/2π is an absolute lower bound for the comoving temperature along the hyperbolic flow lines. We also present a method to determine the entropy current, and we find that at the Unruh temperature the...
We discuss chiral fermions in gauge (and gravitational) backgrounds,
and focus on the structure of their trace anomalies.
We regulate the quantum theory with Pauli-Villars fields
and do not find party-odd terms in the trace anomalies.
The latter have been the object of recent analyses.
In various cosmological models, the curvature perturbation $\zeta$ has a constant solution in the infrared (IR) limit and $\zeta$ fulfills the soft theorem, a.k.a, the consistency relation. However, it has not been very clear what ensures these properties. We show the existence of the constant solution and the soft theorem, assuming the asymptotically FLRW geometry and the invariance under the...
An effective field theory lagrangian formalism of four scalar DoF allows to describe both self gravitating non dissipative fluids and generic massive gravity models as identical systems. We elaborate on the stability of massive gravity models with six DoF and on the behaviour of cosmological perturbations.
In this talk I will expose the features of a new local higher-derivative theory of quantum gravity. The model is based on the concept of “fakeons” or “fake degrees of freedom”, which solves the problem of ghosts and leads to a unitary, renormalizable theory. In particular, I will show the absorptive part of the graviton self-energy at one loop and its contributions to the effective action,...
Numerical Worldline MonteCarlo techniques in flat spacetime have been deeply developed in order to extract physical information from QFT systems. We study a possible way to extend such procedures to the case of (Euclidean) curved spaces, where the proper-time discretization of a bosonic worldline point-particle is treated similarly to a time-slicing regularization for the associated quantum...
In this talk we discuss the possibility that tensor-scalar gravity is naturally scale-invariant, at least at the classical level. This assumption has a number of phenomenological consequences on the physics of the Universe at large scale and of black holes. We consider some of these to assess whether scale-invariance is a viable and fundamental symmetry.
Consequence of gauging 1-form discrete center symmetries are studied in some simple SU(N) gauge theories. In particular, we discuss how the dynamics of strongly coupled chiral gauge theories is constrained by the mixed anomalies involving the new, 1-form symmetries and conventional 0-form symmetries.
We will show how quantization together with quantum dynamics can be simultaneously formulated as the problem of finding an appropriate flat connection (named contact connection) on a Hilbert bundle over a contact manifold. In this setting we will discuss the local, formal gauge equivalence for a broad class of quantum dynamical systems; just as classical dynamics depends on choices of clocks,...
Using the effective action method, we investigate the higher spin actions in flat spacetime that can be obtained by integrating out a fermion field coupled to external higher spin source fields. In particular, an approach based on worldline quantization allows to identify the gauge symmetry of these models and to find the L_infinity structure that characterizes many (classical) field theories,...
In this talk I will present the first-quantized description of Einstein gravity in terms of a point particle model with N=4 local worldline supersymmetries. In particular, I will discuss how the quantum consistency of the underlying first-quantized system produces fully nonlinear Einstein field equations for the target space metric, thus showing that this is not a peculiarity of string...
