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Related papers: Unruh-DeWitt Particle Detectors in Bouncing Cosmol…

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We obtained an exact solution for a uniformly accelerated Unruh-DeWitt detector interacting with a massless scalar field in (3+1) dimensions which enables us to study the entire evolution of the total system, from the initial transient to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Shih-Yuin Lin , B. L. Hu

Response of a circularly rotating Unrh-DeWitt detector to the Minkowski vacuum is investigated. What the detector observes depends on the surface (three volume) to define it by the Hamiltonian. Detectors in the past literature were defined…

General Relativity and Quantum Cosmology · Physics 2013-01-01 Tadas K Nakamura

We have investigated some bouncing models in the framework of an extended gravity theory where the usual Ricci scalar in the gravitational action is replaced by a sum of the Ricci scalar and a term proportional to the trace of the energy…

General Relativity and Quantum Cosmology · Physics 2019-05-24 Sunil Kumar Tripathy , Rakesh Kumar Khuntia , Priyabrata Parida

We investigate the emergence of a quantum Big-Bounce in the context of an isotropic Universe, filled by a self-interacting scalar field, which plays the role of a physical clock. The bouncing cosmology is the result of a scattering process,…

General Relativity and Quantum Cosmology · Physics 2024-10-04 S. Lo Franco , G. Montani

We study the dynamics of states perturbatively expanded about a harmonic system of loop quantum cosmology, exhibiting a bounce. In particular, the evolution equations for the first and second order moments of the system are analyzed. These…

General Relativity and Quantum Cosmology · Physics 2011-01-20 Martin Bojowald , David Mulryne , William Nelson , Reza Tavakol

The proper time of an observer can be introduced as a degree of freedom in quantum cosmology, additional to the existing fields. We review two arguments for using the Schr\"odinger equation to evolve the corresponding wavefunction. We…

High Energy Physics - Theory · Physics 2026-03-25 Federico Piazza , Siméon Vareilles

In the lack of a full-fledged theory of quantum gravity, I consider free, scalar, quantum fields on curved spacetimes to gain insight into the interaction between quantum and gravitational phenomena. I employ the Unruh-DeWitt detector…

General Relativity and Quantum Cosmology · Physics 2022-03-21 Lissa de Souza Campos

We construct the detection rate for particle detectors moving along non-inertial trajectories and interacting with quantum fields. The detectors described here are characterized by the presence of records of observation throughout their…

Quantum Physics · Physics 2015-06-19 Charis Anastopoulos , Ntina Savvidou

The quantum cosmology of the flat Friedmann-Lema{\^i}tre-Robertson-Walker Universe, filled with a scalar field, is considered in the de Broglie-Bohm (dBB) interpretation framework. A stiff-matter quantum bounce solution is obtained. The…

General Relativity and Quantum Cosmology · Physics 2023-07-24 G. S. Vicente , Rudnei O. Ramos , Vitória N. Magalhães

We examine non-singular bounce cosmology within the framework of a phantom scalar field coupled to the Gauss-Bonnet term in both non-viscous and bulk-viscous cases. Using the scale factor ansatz…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-07 Khandro K. Chokyi , Surajit Chattopadhyay

We show that the predictions of spatially smeared particle detectors coupled to quantum fields are not generally covariant outside the pointlike limit. This lack of covariance manifests itself as an ambiguity in the time-ordering operation.…

Quantum Physics · Physics 2021-01-19 Eduardo Martín-Martínez , T. Rick Perche , Bruno de S. L. Torres

We investigate the application of deformation quantization to the system of a free particle evolving within a universe described by a Friedmann-Lemaitre-Robertson-Walker (FLRW) geometry. This approach allows us to analyze the dynamics of…

General Relativity and Quantum Cosmology · Physics 2024-12-19 Alfonso F. Bobadilla , Jose A. R. Cembranos

We demonstrate that the recently introduced evanescent particles of a massive scalar field can be emitted and absorbed by an Unruh-DeWitt detector. In doing so the particles carry away from or deposit on the detector a quantized amount of…

High Energy Physics - Theory · Physics 2024-02-01 Daniele Colosi , Robert Oeckl , Adamantia Zampeli

In quantum cosmology, one has to select a specific wave function solution of the quantum state equations under consideration in order to obtain concrete results. The simplest choices have been already explored, in different frameworks,…

General Relativity and Quantum Cosmology · Physics 2021-09-06 P. C. M. Delgado , N. Pinto-Neto

A companion paper provides a proposal for cosmic singularity resolution based upon general features of a bouncing unitary cosmological model in the mini-superspace approximation. This paper analyses novel phenomenology that can be…

General Relativity and Quantum Cosmology · Physics 2018-12-17 Sean Gryb , Karim P. Y. Thébault

We examine the Unruh-DeWitt particle detector coupled to a scalar field in an arbitrary Hadamard state in four-dimensional curved spacetime. Using smooth switching functions to turn on and off the interaction, we obtain a regulator-free…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Jorma Louko , Alejandro Satz

We investigate the quantum field theory of a Lorentz non-invariant model with a massive nonlinear dispersion relation in Minkowski space. The model involves some non-causal signals in the form of wave packets propagating with super-luminal…

High Energy Physics - Theory · Physics 2009-04-30 R. Rashidi , N. Khosravi , E. Khajeh , H. Salehi

We firstly generalize the massive scalar propagator for planar gravitational waves propagating on Minkowski space obtained recently in Ref. [1]. We then use this propagator to study the response of a freely falling Unruh-DeWitt detector to…

General Relativity and Quantum Cosmology · Physics 2022-12-21 Tomislav Prokopec

We develop a localized particle detector model formulated as a massive quantum field on Minkowski spacetime with the spatial origin excised. To render the problem well-posed at the puncture, we impose boundary conditions at the excised…

High Energy Physics - Theory · Physics 2026-02-12 Victor Hugo M. Ramos , João Paulo M. Pitelli , João C. A. Barata

We examine an Unruh-DeWitt particle detector coupled to a scalar field in three-dimensional curved spacetime. We first obtain a regulator-free expression for the transition probability in an arbitrary Hadamard state, working within…

General Relativity and Quantum Cosmology · Physics 2012-10-09 Lee Hodgkinson , Jorma Louko