3 papers
hep-th2026
Covariant extrinsic curvature expansion of the nonlocal effective action for a massless scalar field on a manifold with boundary
A. Boasso, C. D. Fosco, B. C. Guntsche +1
We study the nonlocal effective action of a massless scalar field defined on a flat manifold with a curved boundary. Using a heat-kernel approach, we derive a covariant expansion o…
hep-th2025
Vacuum polarization in the horizonless Bardeen metric
Andrés Boasso, Francisco D. Mazzitelli
We compute the renormalized stress-energy tensor for a massless quantum scalar field in the background of the horizonless Bardeen spacetime. Within the weak-field approximation, we…
hep-th2024
Nonlocal effective action and particle creation in dimensions
Andrés Boasso, Sebastián Franchino-Viñas, Francisco D. Mazzitelli
We compute the particle creation rate in the context of quantum fields in curved spacetimes, by evaluating the imaginary part of the effective action up to second order in the curv…