6 papers
The price of regularity: core gradient instability in nonsingular dyonic black holes
Lodovico Capuano, Alessandro Longo
Spacetime singularities displayed by classical black hole solutions are expected to be cured by high-energy effects, beyond the regime of validity of General Relativity. On the oth…
Toward the CompactHedron: Bounds on Neutron Stars from Microscopic Principles
Thomas Apostolidis, Alessandro Longo, Borna Salehian +1
We investigate the implications of causality and positivity for the tidal Love numbers of gravitating objects. We work within the framework of point-particle effective field theory…
On the Asymptotic Causal Structure in Gravitational EFTs
Bruno Bucciotti, Paolo Creminelli, Alessandro Longo +2
It is usually assumed that a healthy EFT should not allow superluminal propagation. In the presence of gravity, however, the notion of superluminality becomes subtle, since there i…
Analyticity and positivity of Green's functions without Lorentz
Paolo Creminelli, Alessandro Longo, Borna Salehian +1
We study the properties imposed by microcausality and positivity on the retarded two-point Green's function in a theory with spontaneous breaking of Lorentz invariance. We assume i…
To the Problem of Cosmic Expansion in Massive Gravity
Lavinia Heisenberg, Alessandro Longo, Giovanni Tambalo +1
We consider evolving, spatially flat isotropic and homogeneous (FLRW) cosmologies in ghost-free (dRGT) massive gravity. In this theory, no dynamical flat FLRW background exists if…
Non-analyticity of the -matrix with spontaneously broken Lorentz invariance
Paolo Creminelli, Matteo Delladio, Oliver Janssen +2
We study the -matrix of Goldstones in the renormalizable theory of a complex scalar at finite charge, i.e. in a state that breaks Lorentz invariance. The theory is weakly…