9 papers
Robustness of the primordial power spectrum in hybrid loop quantum cosmology to approximations near the bounce
Kristina Giesel, Almudena Guillén, Guillermo A. Mena Marugán +1
We prove the robustness of the analytic approximation used in (hybrid) loop quantum cosmology to compute the primordial power spectrum of the cosmological perturbations for a recen…
Generalising gravitationally induced decoherence beyond linear environmental interactions in a microscopic quantum mechanical toy model
Max Joseph Fahn, Renata Ferrero, Kristina Giesel +1
We generalise the quantum mechanical toy model for gravitationally induced decoherence presented in Xu, Blencowe (2022) and Domi et al. (2024). In contrast to earlier formulations,…
Formation of shell-crossing singularities in effective gravitational collapse models with bounded and unbounded polymerizations
Francesco Fazzini, Kristina Giesel, Eric Rullit
We extend the investigation into the formation of shell-crossing singularites (SCS) in effective polymerized LTB models to the LQG-inspired asymmetric bounce model, as well as to e…
Investigation of the gravitational dust collapse of the LQG-inspired effective asymmetric bounce model
Kristina Giesel, Hongguang Liu, Eric Rullit
We investigate gravitational dust collapse within an effective loop quantum gravity (LQG)-inspired model exhibiting an asymmetric bounce in the marginally bound case. This work ext…
A gravitationally induced decoherence model for photons in the context of the relational formalism
Max Joseph Fahn, Kristina Giesel, Roman Kemper
We formulate a model of gravitationally induced decoherence for photons starting from Maxwell theory coupled to linearised gravity, expressed in terms of Ashtekar-Barbero variables…
From Principles to Effective Models: A Constructive Framework for Effective Covariant Actions with a Unique Vacuum Solution
Kristina Giesel, Hongguang Liu
The absence of Birkhoff's theorem in effective quantum gravity models leads to a fundamental ambiguity in the vacuum sector, where a priori no unique vacuum solution exists. As a r…