Blue-tilted Tensor Spectrum and Thermal History of the Universe

Abstract

We investigate constraints on the spectral index of primordial gravitational waves (GWs), paying particular attention to a blue-tilted spectrum. Such constraints can be used to test a certain class of models of the early Universe. We investigate observational bounds from LIGO+Virgo, pulsar timing and big bang nucleosynthesis, taking into account the suppression of the amplitude at high frequencies due to reheating after inflation and also late-time entropy production. Constraints on the spectral index are presented by changing values of parameters such as reheating temperatures and the amount of entropy produced at late time. We also consider constraints under the general modeling approach which can approximately describe various scenarios of the early Universe. We show that the constraints on the blue spectral tilt strongly depend on the underlying assumption and, in some cases, a highly blue-tilted spectrum can still be allowed.

24 pages, 16 figures

References in corpus (34)

• G-inflation: inflation driven by the Galileon field
• Gravitational Waves from Phase Transitions at the Electroweak Scale and Beyond
• Upper bounds on the low-frequency stochastic gravitational wave background from pulsar timing observations: current limits and future prospects
• Theory and Numerics of Gravitational Waves from Preheating after Inflation
• Improved Calculation of the Primordial Gravitational Wave Spectrum in the Standard Model
• Toward an Understanding of Foreground Emission in the BICEP2 Region
• A Gravitational Wave Background from Reheating after Hybrid Inflation
• Gravitational waves from stochastic relativistic sources: primordial turbulence and magnetic fields
• Gravitational Wave Production At The End Of Inflation
• A stochastic background of gravitational waves from hybrid preheating
• A new cosmic microwave background constraint to primordial gravitational waves
• Relating gravitational wave constraints from primordial nucleosynthesis, pulsar timing, laser interferometers, and the CMB: implications for the early universe
• Probing reheating temperature of the universe with gravitational wave background
• Tensor Modes from a Primordial Hagedorn Phase of String Cosmology
• A joint analysis of Planck and BICEP2 B modes including dust polarization uncertainty
• Precision calculations of the gravitational wave background spectrum from inflation
• Improved Upper Limits on the Stochastic Gravitational-Wave Background from 2009-2010 LIGO and Virgo Data
• Blue Tensor Spectrum from Particle Production during Inflation
• Detectability of Gravitational Waves from Phase Transitions
• Prospects for direct detection of primordial gravitational waves
• Search for a stochastic background of 100-MHz gravitational waves with laser interferometers
• Space laser interferometers can determine the thermal history of the early Universe
• Nonlinear Inflaton Fragmentation after Preheating
• Fingerprints of Galactic Loop I on the Cosmic Microwave Background
• Observational constraints on patch inflation in noncommutative spacetime
• Closed String Thermodynamics and a Blue Tensor Spectrum
• The gravitational wave background from super-inflation in Loop Quantum Cosmology
• Observational Constraints on Theories with a Blue Spectrum of Tensor Modes
• Spectral distortions from the dissipation of tensor perturbations
• Reconstruction of the primordial power spectra with Planck and BICEP2
• Inflation and Alternatives with Blue Tensor Spectra
• Blue Gravity Waves from BICEP2 ?
• Blue running of the primordial tensor spectrum
• Is Cosmology Compatible with Blue Gravity Waves ?

Cited by in corpus (55)

• The NANOGrav 15-year Data Set: Search for Signals from New Physics
• Science with the space-based interferometer LISA. IV: Probing inflation with gravitational waves
• New Horizons for Fundamental Physics with LISA
• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Implications of the NANOGrav results for inflation
• Inflationary interpretation of the stochastic gravitational wave background signal detected by pulsar timing array experiments
• Primordial gravitational waves from NANOGrav: a broken power-law approach
• Cosmological Background Interpretation of Pulsar Timing Array Data
• Decoding the phases of early and late time reheating through imprints on primordial gravitational waves
• Blue-tilted inflationary tensor spectrum and reheating in the light of NANOGrav results
• Spectrum of Primordial Gravitational Waves in Modified Gravities: A Short Overview
• Multi-wavelength constraints on the inflationary consistency relation
• Intermittent null energy condition violations during inflation and primordial gravitational waves
• Broken blue-tilted inflationary gravitational waves: a joint analysis of NANOGrav 15-year and BICEP/Keck 2018 data
• Inflation, the Hubble Tension and Early Dark Energy: an alternative overview
• Implications of the NANOGrav result on primordial gravitational waves in nonstandard cosmologies
• Probing The Early Universe Cosmology With NANOGrav: Possibilities and Limitations
• NANOGrav signal and LIGO-Virgo Primordial Black Holes from the Higgs field
• Towards a reliable calculation of relic radiation from primordial gravitational waves
• Fingerprint of GeV scale right-handed neutrinos on inflationary gravitational waves and PTA data
• Effects of the Axion Through the Higgs Portal on Primordial Gravitational Waves During the Electroweak Breaking
• Inflationary Potential as seen from Different Angles: Model Compatibility from Multiple CMB Missions
• Measuring Inflaton Couplings via Primordial Gravitational Waves
• Impact of high-scale Seesaw and Leptogenesis on inflationary tensor perturbations as detectable gravitational waves
• Generating enhanced parity-violating gravitational waves during inflation with violation of the null energy condition
• Null energy condition violation during inflation and pulsar timing array observations
• Nanohertz gravitational waves from NEC violation in the early universe
• Gravitational Waves-Tomography of Low-Scale-Leptogenesis
• Amplification of the Primordial Gravitational Waves Energy Spectrum by a Kinetic Scalar in $F(R)$ Gravity
• Generating enhanced primordial GWs during inflation with intermittent violation of NEC and diminishment of GW propagating speed
• Probing the primordial universe with gravitational waves detectors
• $f(R)$-Gravity Generated Post-inflationary Eras and their Effect on Primordial Gravitational Waves
• Tracking the Multifield Dynamics with Cosmological Data: A Monte Carlo approach
• Implication of Pulsar Timing Array Experiments on Cosmological Gravitational Wave Detection
• Impact of memory-burdened black holes on primordial gravitational waves in light of Pulsar Timing Array
• Enhanced primordial gravitational waves from a stiff post-inflationary era due to an oscillating inflaton
• Tomography of flavoured leptogenesis with primordial blue gravitational waves
• Gravitational-wave background in bouncing models from semi-classical, quantum and string gravity
• Probing flavor violation and baryogenesis via primordial gravitational waves
• Choosing suitable noise models for nanohertz gravitational-wave astrophysics
• Crescendo Beyond the Horizon: More Gravitational Waves from Domain Walls Bounded by Inflated Cosmic Strings
• Climbing over the potential barrier during inflation via null energy condition violation
• Probing PeV scale SUSY-breaking with Satellite Galaxies and Primordial Gravitational Waves
• Quantum gravity and gravitational-wave astronomy
• Gravitational waves in a cyclic Universe: resilience through cycles and vacuum state
• Neutrino masses and gravitational wave background
• Log-periodic gravitational-wave background beyond Einstein gravity
• An SZ-Like Effect on Cosmological Gravitational Wave Backgrounds
• Connecting Inflation to the NANOGrav 15-year Data Set via Massive Gravity
• Testing quantum gravity with primordial gravitational waves
• Gravitational waves from axion inflation in the gradient expansion formalism. Part II. Fermionic axion inflation
• Implications of pulsar timing arrays for Gauss-Bonnet Inflation
• Axion Dark Matter Archaeology with Primordial Gravitational Waves
• SageNet: Fast Neural Network Emulation of the Stiff-amplified Gravitational Waves from Inflation
• Primordial gravitational waves: Model effects on time evolution and spectrum