activity
20242026
collaborators

7 papers

astro-ph.CO2026

Gravitational waves from super-Hubble bubbles

Pulkit S. Ghoderao, Arttu Rajantie, Danièle Steer

We consider a cosmological first-order phase transition in which bubbles of true vacuum nucleate during inflation but do not collide and percolate until the Universe has entered th…

hep-th2026

Asymptotic limits of constrained instantons

Benjamin Elder, Kinga Gawrych, Arttu Rajantie

We revisit the topic of false vacuum decay in field theory. We focus on a toy model of a real massive scalar field with an unstable quartic potential. This model has a false vacuum…

hep-th2026

Scalar field effective potentials in de Sitter spacetime

Lucas Vicente García-Consuegra, Arttu Rajantie

We investigate two different definitions of a scalar field effective potential in quantum field theory in de Sitter spacetime: the standard textbook definition, and the constraint…

hep-th2026

Constrained instantons in scalar field theories

Benjamin Elder, Kinga Gawrych, Arttu Rajantie

Instantons, localised saddle points of the action, play an important role in describing non-perturbative aspects of quantum field theories, for example vacuum decay or violation of…

astro-ph.CO2025

Curvature perturbations from vacuum transition during inflation

Björn Garbrecht, Pulkit S. Ghoderao, Arttu Rajantie

We demonstrate that in the presence of a light scalar spectator field, vacuum transitions taking place during inflation can produce large, potentially detectable non-Gaussian signa…

hep-ex2025

Search for Highly-Ionizing Particles in pp Collisions During LHC Run-2 Using the Full MoEDAL Detector

MoEDAL Collaboration

This search for Magnetic Monopoles (MMs) and High Electric Charge Objects (HECOs) with spins 0, 1/2 and 1, uses for the first time the full MoEDAL detector, exposed to 6.6 fb^-1 pr…