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001-es BibID:	BIBFORM108061
035-os BibID:	(cikkazonosító)062 (WOS)000779813100006 (Scopus)85128410375
Első szerző:	Márián István Gábor (fizikus)
Cím:	Vacuum energy and renormalization of the field-independent term / I. G. Márián, U. D. Jentschura, N. Defenu, A. Trombettoni, I. Nándori
Dátum:	2022
ISSN:	1475-7516
Megjegyzések:	Due to its construction, the nonperturbative renormalization group (RG) evolution of the constant, field-independent term (which is constant with respect to field variations but depends on the RG scale k) requires special care within the Functional Renormalization Group (FRG) approach. In several instances, the constant term of the potential has no physical meaning. However, there are special cases where it receives important applications. In low dimensions (d = 1), in a quantum mechanical model, this term is associated with the ground-state energy of the anharmonic oscillator. In higher dimensions (d = 4), it is identical to the A term of the Einstein equations and it plays a role in cosmic inflation. Thus, in statistical field theory, in flat space, the constant term could be associated with the free energy, while in curved space, it could be naturally associated with the cosmological constant. It is known that one has to use a subtraction method for the quantum anharmonic oscillator in d = 1 to remove the k 2 term that appears in the RG flow in its high-energy (UV) limit in order to recover the correct results for the ground-state energy. The subtraction is needed because the Gaussian fixed point is missing in the RG flow once the constant term is included. However, if the Gaussian fixed point is there, no further subtraction is required. Here, we propose a subtraction method for k(4) and k(2) terms of the UV scaling of the RG equations for d = 4 dimensions if the Gaussian fixed point is missing in the RG flow with the constant term. Finally, comments on the application of our results to cosmological models are provided.
Tárgyszavak:	Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Journal of Cosmology and Astroparticle Physics. - 2022 : 03 (2022), p. -. -
További szerzők:	Jentschura, Ulrich David (fizikus) Defenu, N. Trombettoni, Andrea Nándori István (1973-) (fizikus)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM088496
Első szerző:	Márián István Gábor (fizikus)
Cím:	Renormalization-group running induced cosmic inflation / I. G. Márián, N. Defenu, U. D. Jentschura, A. Trombettoni, I. Nándori
Dátum:	2020
ISSN:	1475-7516
Megjegyzések:	As a contribution to a viable candidate for a standard model of cosmology, we here show that pre-inflationary quantum fluctuations can provide a scenario for the long- sought initial conditions for the inflaton field. Our proposal is based on the assumption that at very high energies (higher than the energy scale of inflation) the vacuum-expectation value (VeV) of the field is trapped in a false vacuum and then, due to renormalization-group (RG) running, the potential starts to flatten out toward low energy, eventually tending to a convex one which allows the field to roll down to the true vacuum. We argue that the proposed mechanism should apply to large classes of inflationary potentials with multiple concave regions. Our findings favor a particle physics origin of chaotic, large-field inflationary models as we eliminate the need for large field fluctuations at the GUT scale. In our analysis, we provide a specific example of such an inflationary potential, whose parameters can be tuned to reproduce the existing cosmological data with good accuracy.
Tárgyszavak:	Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Journal of Cosmology and Astroparticle Physics. - 2020 : 06 (2020), p. 028-028. -
További szerzők:	Defenu, N. Jentschura, Ulrich David (fizikus) Trombettoni, Andrea Nándori István (1973-) (fizikus)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon: