Results 11 to 20 of about 7,077 (267)
Magnetic-induced spontaneous scalarization in dynamical Chern–Simons gravity
European Physical Journal C: Particles and Fields, 2023 In the framework of the dynamical Chern–Simons gravity, we study the scalar field perturbations of the Reissner–Nordström–Melvin spacetime, which describes a charged black hole permeated by a uniform magnetic field. In the presence of the magnetic field,
Shao-Jun Zhang +3 more
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SCALAR PERTURBATIONS IN A PRIMORDIAL INFLATIONARY SCENARIO [PDF]
International Journal of Modern Physics A, 2001 We compute the spectral index for scalar perturbations generated in a primordial inflationary model2. In this model, the transition of the inflationary phase to the radiative era is achieved through the decay of the cosmological term leading a second order phase transition and the characteristics of the model allow to implement a set of initial ...
Fabris, Julio C., Spindel, Philippe
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CMB imprints of non-canonical anisotropic inflation
European Physical Journal C: Particles and Fields, 2021 Effect of non-canonical scalar fields on the CMB imprints of the anisotropic inflation will be discussed in details in this paper. In particular, we are able to obtain the general formalism of the angular power spectra in the scalar perturbations, tensor
Tuan Q. Do, W. F. Kao, Ing-Chen Lin
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Chiral Perturbation Theory with an Isosinglet Scalar [PDF]
Proceedings of XIII Quark Confinement and the Hadron Spectrum — PoS(Confinement2018), 2019 We present an extension of chiral perturbation theory that explicitly includes an isosinglet scalar in the Lagrangian. The dynamical effects from the scalar state is of phenomenological relevance in theories where the mass of the isosinglet scalar is comparable to the mass of the pseudo-Goldstone bosons.
Hansen, Martin +2 more
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Perturbations in a scalar field model with virtues of ΛCDM [PDF]
Journal of Cosmology and Astroparticle Physics, 2021 Abstract In the era of precision cosmology, the cosmological constant Λ gives quite an accurate description of the evolution of the Universe, but it is still plagued with the fine-tuning problem and the cosmic coincidence problem. In this work, we investigate the perturbations in a scalar field model that drives the recent acceleration ...
Sinha, Srijita, Banerjee, Narayan
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Generating cosmological perturbations in non-singular Horndeski cosmologies
Journal of High Energy Physics, 2023 We construct a concrete model of Horndeski bounce with strong gravity in the past. Within this model we show that the correct spectra of cosmological perturbations may be generated at early contracting epoch, with mild fine-tuning ensuring that the ...
Yulia Ageeva +2 more
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Primordial perturbations of test scalar fields [PDF]
Physical Review D, 2007 4 pages, no figures, clarifications and refs.
Piao, Yun-Song, Zhang, Yuan-Zhong
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Scalar and tensor perturbations in DHOST bounce cosmology [PDF]
Journal of Cosmology and Astroparticle Physics, 2021 Abstract We investigate the bounce realization in the framework of DHOST cosmology, focusing on the relation with observables. We perform a detailed analysis of the scalar and tensor perturbations during the Ekpyrotic contraction phase, the bounce phase, and the fast-roll expansion phase, calculating the power spectra, the ...
Zhu, Mian +4 more
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Quantum corrections to slow-roll inflation: scalar and tensor modes
Journal of High Energy Physics, 2021 Inflation is often described through the dynamics of a scalar field, slow-rolling in a suitable potential. Ultimately, this inflaton must be identified with the expectation value of a quantum field, evolving in a quantum effective potential. The shape of
Jens O. Andersen +2 more
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Scalar and tensor perturbations in vacuum inflation [PDF]
Classical and Quantum Gravity, 2017 Recently, it was proposed that a small true vacuum universe can inflate spontaneously, in principle. Furthermore, there should be matter creation in vacuum inflation due to quantum fluctuations, and the matter created will influence the inflation simultaneously.
Huang, Zhiqiang +2 more
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