arXiv subjects

Mischa Salle

Publications and source records attributed to Mischa Salle.

3 recordsLinked to original sources

arXiv2025

A matter of perspective: how nanoscale optical defects limit cosmic-scale gravitational wave observations

Ground-based gravitational-wave (GW) detectors, such as LIGO, Virgo, and KAGRA, have revolutionised as- tronomy. Now, future detectors like the Einstein Telescope and Cosmic Explorer aim to achieve even greater sensitivity. Advanced optical simulations are crucial to overcoming the challenges faced by these complex in- terferometers. Finesse, the leading interferometer simulation tool in the GW community, supports the design and commissioning of these detectors by modeling optical, quantum, and mechanical effects. A key focus is understanding optical defects that distort the shape of the laser light and limit detector performance. This work explores how nanoscale defects affect GW observations and presents recent advancements in modeling their effects to guide the development of next-generation detector optics.

physics.optics↗

arXiv2004

Kinks in the Hartree approximation

The topological defects of the lambda phi^4 theory, kink and antikink, are studied in the Hartree approximation. This allows us to discuss quantum effects on the defects in both stationary and dynamical systems. The kink mass is calculated for a number of parameters, and compared to classical, one loop and Monte Carlo results known from the literature. We discuss the thermalization of the system after a kink antikink collision. A classical result, the existence of a critical speed, is rederived and shown for the first time in the quantum theory. We also use kink antikink collisions as a very simple toy model for heavy ion collisions and discuss the differences and similarities, for example in the pressure. Finally, using the Hartree Ensemble Approximation allows us to study kink antikink nucleation starting from a thermal (Bose Einstein) distribution. In general our results indicate that on a qualitative level there are few differences with the classical results, but on a quantitative level there are some import ones.

hep-ph↗

arXiv2003

The Hartree ensemble approximation revisited: The "symmetric phase"

The Hartree ensemble approximation is studied in the ``symmetric phase'' of 1+1 dimensional lambda phi^4 theory. In comparison with the ``broken phase'' studied previously, it is shown that the dynamical evolution of observables such as the particle distribution, energy exchange and auto-correlation functions, is substantially slower. Approximate thermalization is found only for relatively large energy densities and couplings.

hep-ph↗