Planck scale effects on the stochastic gravitational wave background generated from cosmological hadronization transition: A qualitative study

Abstract

We reconsider the stochastic gravitational wave background spectrum produced during the first order hadronization process, in presence of ultraviolet cutoffs suggested by the generalized uncertainty principle as a promising signature towards the Planck scale physics. Unlike common perception that the dynamics of QCD phase transition and its phenomenological consequences are highly influenced by the critical temperature, we find that the underlying Planck scale modifications can affect the stochastic gravitational spectrum arising from the QCD transition without a noteworthy change in the relevant critical temperature. Our investigation shows that incorporating the natural cutoffs into MIT bag equation of state and background evolution leads to a growth in the stochastic gravitational power spectrum, while the relevant redshift of the QCD era, remains unaltered. These results have double implications from the point of view of phenomenology. Firstly, it is expected to enhance the chance of detecting the stochastic gravitational signal created by such a transition in future observations. Secondly, it gives a hint on the decoding from the dynamics of QCD phase transition.

The quark chemical potential of QCD phase transition and the stochastic background of gravitational waves

“…In this respect to have a proper EoS becomes therefore crucial, especially when the stochastic background of GWs generated by any PT is known. It severely depends on the critical temperature 4 T * (in particular here T * (QCD) ∼ a few hundred MeV), [24,27,28].…”

“…In Refs. [24,28], frequencies related to other GW sources are discussed. 3 Recall that, in high energy regime, QCD is an asymptotic freedom and perturbative theory while, at low energy, it is strongly-coupled so that a perturbative approach is not useful [26].…”

“…3 Recall that, in high energy regime, QCD is an asymptotic freedom and perturbative theory while, at low energy, it is strongly-coupled so that a perturbative approach is not useful [26]. 4 In [28], it is shown, in the Planck physics extended framework, assuming some natural cutoffs on the length and momentum of particles into QCD thermodynamic, that the stochastic GW background results affected even in the absence of change in the critical temperature. 5 More precisely, although at end of QCD-PT the ratio of quark density number to photon number density η = nq nγ may be tiny, of the order of ≃ 10 −10 − 10 −9 (as required by primordial nucleosynthesis), at temperatures above critical temperature (QGP phase) it is order of unity [31] and [32].…”

Minimal length, maximal momentum and stochastic gravitational waves spectrum generated from cosmological QCD phase transition

“…Now, we set Eqs. (33) and (34) into Ω gw * h 2 = Ω bwc gw * (ν) + Ω mhd gw * (ν) h 2 and then use it into Eq. ( 26).…”

“…So GUP modified equation of state will be reasonable to use in the study of the SGWB power spectrum. In this context, the GUP modified equations of state have been used to study the SGWP power spectrum in [33,34], and the possibility of detection of the SGWB signal has been discussed. In this paper, we intend to investigate the power spectrum of SGWB with linear quadratic GUP to study qualitatively whether the detection is more probable in the current epoch.…”