3 papers
hep-th2025
Toward quantum tunneling from excited states: Recovering imaginary-time instantons from a real-time analysis
Thomas Steingasser, David I. Kaiser
We revisit the path integral description of quantum tunneling and lay the groundwork for its generalization to excites states through real-time path integral techniques. For clarit…
hep-ph2025
Precision Unitarity Calculations in Inflationary Models
Thomas Steingasser, Mark P. Hertzberg, David I. Kaiser
We revisit perturbative unitarity in scalar field inflation with a nonminimal coupling, with Higgs inflation serving as the most prominent example. Although such models are phenome…
hep-th2025
Finite-Temperature Instantons from First Principles
Thomas Steingasser, Morgane König, David I. Kaiser
We derive the finite-temperature quantum-tunneling rate from first principles. The rate depends on both real- and imaginary-time; we demonstrate that the relevant instantons should…