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Related papers: Quantumness of relic gravitons

200 papers

Appearance of cosmic strings in the early Universe is a common manifestation of new physics typically linked to some high energy scale. In this paper, we discuss a different situation, where a model underlying cosmic string formation is…

High Energy Physics - Phenomenology · Physics 2022-02-02 William T. Emond , Sabir Ramazanov , Rome Samanta

We study the dynamics of a coherent state of closed type II string gravitons within the framework of the Steepest Entropy Ascent Quantum Thermodynamics, an effective model where the quantum evolution is driven by a maximal increase of…

High Energy Physics - Theory · Physics 2024-11-25 Cesar Damian , Oscar Loaiza-Brito

We theoretically study nonperturbative strong-coupling phenomena in cavity magnonics systems in which the uniform magnetization dynamics (magnons) in a ferromagnet is coupled to the microwave magnetic field (photons) of a single LC…

Mesoscale and Nanoscale Physics · Physics 2025-11-05 Takahiro Chiba , Ryunosuke Suzuki , Takashi Otaki , Hiroaki Matsueda

We propose to uncover the signature of a stringy era in the primordial Universe by searching for a prominent peak in the relic graviton spectrum. This feature, which in our specific model terminates an $\omega^3$ increase and initiates an…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Massimo Galluccio , Marco Litterio , Franco Occhionero

Scalar particles traveling faster than a subluminal gravitational wave generate gravitons via gravitational Cherenkov radiation. In this paper, we investigate graviton production by the primordial plasma within the framework of modified…

General Relativity and Quantum Cosmology · Physics 2025-01-06 Paola C. M. Delgado , Alexander Ganz , Chunshan Lin , Roxane Thériault

The construction of quantum field theory (QFT) of a free massive scalar field with respect to a general congruence of observers is considered, the splitting into positive- and negative-frequency modes being defined by diagonalization of the…

High Energy Physics - Theory · Physics 2018-12-13 P. O. Kazinski

Tentative evidence suggests that the cores of massive neutron stars consist of deconfined quark matter. We argue that the formation of such a quark matter core during a galactic supernova could be accompanied by the emission of…

High Energy Physics - Phenomenology · Physics 2026-03-20 Katarina Bleau , Joachim Kopp , Jiheon Lee , Jorinde van de Vis

Density contrasts in the universe are governed by scalar cosmological perturbations which, when expressed in terms of gauge-invariant variables, contain a classical component from scalar metric perturbations and a quantum component from…

General Relativity and Quantum Cosmology · Physics 2022-01-11 Jen-Tsung Hsiang , Bei-Lok Hu

It is a general belief that all fundamental interactions need to be quantized. However, all attempts to develop a quantum theory of gravity presented various problems, leading to a recent active debate about how to probe its quantum nature.…

Quantum Physics · Physics 2018-06-25 Salvatore M. Giampaolo , Tommaso Macrì

A lower bound on the amount of noise that must be added to a GHZ-like entangled state to make it separable (also called the random robustness) is found using the transposition condition. The bound is applicable to arbitrary numbers of…

Quantum Physics · Physics 2009-11-06 P. Deuar , W. J. Munro , K. Nemoto

The main obstacle in attempts to construct a consistent quantum gravity is the absence of independent flat time. This can in principle be cured by going out to higher dimensions. The modern paradigm assumes that the fundamental theory of…

High Energy Physics - Theory · Physics 2008-11-26 A. V. Smilga

We show that the self-interactions present in the effective field theory formulation of general relativity can couple gravitational wave modes and generate nonclassical states. The output of gravitational nonlinear processes can also be…

General Relativity and Quantum Cosmology · Physics 2025-12-05 Thiago Guerreiro

It is shown by the author that if gravitons are super-strong interacting particles and the low-temperature graviton background exists, the basic cosmological conjecture about the Dopplerian nature of redshifts may be false. In this case, a…

High Energy Physics - Theory · Physics 2007-05-23 Michael A. Ivanov

A spectrum of relic stochastic gravitational radiation, strongly tilted towards high frequencies, and characterized by two basic parameters is shown to emerge in a class of string theory models. We estimate the required sensitivity for…

High Energy Physics - Theory · Physics 2007-05-23 R. Brustein , M. Gasperini , M. Giovannini , G. Veneziano

We show that the spectral energy distribution of relic gravitons mildly increases for frequencies smaller than the $\mu$Hz and then flattens out whenever the refractive index of the tensor modes is dynamical during a quasi-de Sitter stage…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-22 Massimo Giovannini

The stochastic gravitational-wave background (SGWB) produced by merging neutron stars exhibits a peak in the kHz band. In this paper, we develop a theoretical framework to exploit this distinctive feature through a Markov Chain Monte Carlo…

General Relativity and Quantum Cosmology · Physics 2024-04-04 Giulia Capurri , Andrea Lapi , Mario Spera , Carlo Baccigalupi

The spectrum of thermal gravitational waves is obtained by including the high frequency thermal gravitons created from extra-dimensional effect and is a new feature of the spectrum. The amplitude and spectral energy density of gravitational…

General Relativity and Quantum Cosmology · Physics 2013-06-21 Basem Ghayour , P K Suresh

In this essay it is proved that, in a self-consistent semiclassical theory of gravity, the asymptotically measured orbital periods of test particles around central compact objects are fundamentally bounded from below by the compact…

General Relativity and Quantum Cosmology · Physics 2025-04-16 Shahar Hod

In this thesis, we focus on higher-curvature extensions of Einstein gravity as toy models to probe universal properties of conformal field theory (CFT) using the gauge/gravity duality. In this context, we are particularly interested in…

High Energy Physics - Theory · Physics 2022-07-27 Javier Moreno

Quantum Field Theory (QFT) introduced us to the notion that a causal diamond in space-time corresponded to a subsystem of a quantum mechanical system defined on the global space-time. Work by Jacobson\cite{ted95}, Fischler and…

High Energy Physics - Theory · Physics 2025-09-23 T. Banks