NANOGrav hints for first-order confinement-deconfinement phase transition in different QCD-matter scenarios

Abstract

Recent observations from several pulsar timing array (PTA) collaborations have unveiled compelling evidence for a stochastic signal in the nanohertz band. This signal aligns remarkably with a gravitational wave (GW) background, potentially originating from the first-order color charge confinement phase transition. Distinct quantum chromodynamics (QCD) matters, such as quarks or gluons, and diverse phase transition processes thereof can yield disparate GW energy density spectra. In this paper, employing the Bayesian analysis on the NANOGrav 15-year data set, we explore the compatibility with the observed PTA signal of the GW from phase transitions of various QCD matter scenarios in the framework of the holographic QCD. We find that the PTA signal can be effectively explained by the GW from the confinement-deconfinement phase transition of pure quark systems in a hard wall model of the holographic QCD where the bubble dynamics, one important source of the GWs, is of the Jouguet detonations. Notably, our analysis decisively rules out the plausibility of the pure gluon QCD-matter scenario and the non-runaway bubble dynamics model for the phase transition in explaining the observed PTA signal.

7 pages, 2 figures; accepted by PRD

References in corpus (8)

• Gravitational Wave Production by Collisions: More Bubbles
• Gravitational wave generation from bubble collisions in first-order phase transitions: an analytic approach
• Gravitational waves from stochastic relativistic sources: primordial turbulence and magnetic fields
• A Holographic Prediction of the Deconfinement Temperature
• Gravitational Waves from Warped Spacetime
• Gravitional radiation from first-order phase transitions in the presence of a fluid
• Detectability of Gravitational Waves from Phase Transitions
• Searching for continuous Gravitational Waves in the second data release of the International Pulsar Timing Array

Cited by in corpus (12)

• Probing the speed of scalar-induced gravitational waves with pulsar timing arrays
• Realisation of the ultra-slow roll phase in Galileon inflation and PBH overproduction
• Obviating PBH overproduction for SIGWs generated by Pulsar Timing Arrays in loop corrected EFT of bounce
• Charting the Nanohertz Gravitational Wave Sky with Pulsar Timing Arrays
• Can we distinguish the adiabatic fluctuations and isocurvature fluctuations with pulsar timing arrays?
• The Impact of Spin in Compact Binary Foreground Subtraction for Estimating the Residual Stochastic Gravitational-wave Background in Ground-based Detectors
• Untangling PBH overproduction in $w$-SIGWs generated by Pulsar Timing Arrays for MST-EFT of single field inflation
• Constraining string cosmology with the gravitational-wave background using the NANOGrav 15-year data set
• Transition rate and gravitational wave spectrum from first-order QCD phase transitions
• Detecting a Gravitational-Wave Background from Inflation with Null Energy Condition Violation: Prospects for Taiji
• Implications of pulsar timing arrays for Gauss-Bonnet Inflation
• Primordial Black Holes from Spatially Varying Cosmological Constant Induced by Field Fluctuations in Extra Dimensions