Gravitational Waves-Tomography of Low-Scale-Leptogenesis

Abstract

A long-lived scalar field ($\Phi$) which couples weakly to the right-handed (RH) neutrinos ($N_{Ri}$), generates small RH neutrino masses ($M_i$) in Low-Scale-Leptogenesis (LSL) mechanisms, despite having a large vacuum expectation value $v_{\Phi }$. In this case, the correlation shared by the $M_i$s and the duration of the non-standard cosmic history driven by the $\Phi$ provides an excellent opportunity to study LSL signatures on primordial gravitational waves (GWs). We find it engaging, specifically for the gravitational waves that originate due to the inflationary blue-tilted tensor power spectrum and propagate through the non-standard cosmic epoch. Depending on $M_i$, broadly, the scenario has two significant consequences. First, if LSL is at play, GWs with a sizeable blue tilt do not contradict the Big-Bang-Nucleosynthesis (BBN) bound even for the post-inflationary models with very high-scale reheating. Second, it opens up a possibility to probe LSLs via a low-frequency and a complementary high-frequency measurement of GW-spectral shapes which are typically double-peaked. For a case study, we consider the recent results on GWs from the Pulsar-Timing-Arrays (PTAs) as a `measurement' at the low frequencies and forecast the signatures of LSL mechanisms at the higher frequencies.

23 pages, 9 figures, LIGO bound on SGWB updated. Matches the JHEP version

References in corpus (23)

• Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis
• Leptogenesis
• G-inflation: inflation driven by the Galileon field
• On the evidence for a common-spectrum process in the search for the nanohertz gravitational-wave background with the Parkes Pulsar Timing Array
• Improved Calculation of the Primordial Gravitational Wave Spectrum in the Standard Model
• Common-red-signal analysis with 24-yr high-precision timing of the European Pulsar Timing Array: Inferences in the stochastic gravitational-wave background search
• Stochastic gravitational wave background from smoothed cosmic string loops
• Probing reheating temperature of the universe with gravitational wave background
• Flavour Covariant Transport Equations: an Application to Resonant Leptogenesis
• Primordial gravitational waves from NANOGrav: a broken power-law approach
• Precision calculations of the gravitational wave background spectrum from inflation
• Blue-tilted Tensor Spectrum and Thermal History of the Universe
• Decay of Cosmic String Loops Due to Particle Radiation
• Blue-tilted inflationary tensor spectrum and reheating in the light of NANOGrav results
• Leptogenesis triggered by a first-order phase transition
• Generalised tensor fluctuations and inflation
• Gravitational Wave Pathway to Testable Leptogenesis
• Electroweak naturalness in three-flavour Type I see-saw and implications for leptogenesis
• Testing Super-Heavy Dark Matter from Primordial Black Holes with Gravitational Waves
• Probing Miracle-less WIMP Dark Matter via Gravitational Waves Spectral Shapes
• Revisiting slow-roll dynamics and the tensor tilt in general single-field inflation
• Neutrino masses and gravitational wave background
• Probing High Scale Dirac Leptogenesis via Gravitational Waves from Domain Walls

Cited by in corpus (11)

• Inflationary interpretation of the stochastic gravitational wave background signal detected by pulsar timing array experiments
• Fingerprint of GeV scale right-handed neutrinos on inflationary gravitational waves and PTA data
• Impact of high-scale Seesaw and Leptogenesis on inflationary tensor perturbations as detectable gravitational waves
• Gravitational wave signatures of PBH-generated baryon-dark matter coincidence
• Impact of memory-burdened black holes on primordial gravitational waves in light of Pulsar Timing Array
• Tomography of flavoured leptogenesis with primordial blue gravitational waves
• Imprint of PBH domination on gravitational waves generated by cosmic strings
• Probing flavored regimes of leptogenesis with gravitational waves from cosmic strings
• Climbing over the potential barrier during inflation via null energy condition violation
• Complementarity between Cosmic String Gravitational Waves and long-lived particle searches in a laboratory
• Axion Dark Matter Archaeology with Primordial Gravitational Waves