Cross-correlating pulsar timing and polarimetry isolates the circular polarization of isotropic stochastic GW backgrounds and shares the Hellings-Downs angular pattern.
CMB-S4: Forecasting Constraints on Primordial Gravitational Waves
9 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
CMB-S4---the next-generation ground-based cosmic microwave background (CMB) experiment---is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the Universe, from the highest energies at the dawn of time through the growth of structure to the present day. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semi-analytic projection tool, targeted explicitly towards optimizing constraints on the tensor-to-scalar ratio, $r$, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2--3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments given a desired scientific goal. To form a closed-loop process, we couple this semi-analytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for $r > 0.003$ at greater than $5\sigma$, or, in the absence of a detection, of reaching an upper limit of $r < 0.001$ at $95\%$ CL.
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In pure axion inflation, detectable gravitational wave signals arise only in parameter regions with strong backreaction that violate the upper bound on ΔN_eff.
Tensor perturbations from FOPT and domain-wall sources are claimed to induce second-order scalar perturbations large enough to form primordial black holes, potentially all of the dark matter.
Derives conditions on branch parameters for controlled inflationary plateaus in penumbral monodromic valleys, with an exactly solvable family targeting r ~ 10^{-3} and alpha_s ~ -r/2.
Genetic algorithm reconstructs single-field inflationary models with features in the scalar power spectrum that fit Planck 2018 CMB data better by Δχ² ≲ -10 and suggest alternative background parameters.
A swampland-inspired DM-EDE coupling is tested against DESI DR2 BAO data, showing the EDE potential construction affects late-time dark energy constraints.
Expanded Simons Observatory could measure reheating temperature and inflaton-gluon coupling to a few percent in QCD-driven warm inflation if r=0.01 primordial gravitational waves are found.
A memorial review of the Starobinsky inflation model that proposes a deformation for primordial black hole production and discusses superstring quantum corrections plus universal reheating.
The paper reviews cosmological tensions including the H0 and S8 discrepancies and explores new physics models that could explain them.
citing papers explorer
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Detecting Parity-Violating Gravitational Wave Backgrounds with Pulsar Polarization Arrays
Cross-correlating pulsar timing and polarimetry isolates the circular polarization of isotropic stochastic GW backgrounds and shares the Hellings-Downs angular pattern.
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Gravitational waves from axion inflation in the gradient expansion formalism. Part I. Pure axion inflation
In pure axion inflation, detectable gravitational wave signals arise only in parameter regions with strong backreaction that violate the upper bound on ΔN_eff.
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Primordial Black Hole from Tensor-induced Density Fluctuation: First-order Phase Transitions and Domain Walls
Tensor perturbations from FOPT and domain-wall sources are claimed to induce second-order scalar perturbations large enough to form primordial black holes, potentially all of the dark matter.
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Controlled Penumbral Inflation from Monodromic Valleys
Derives conditions on branch parameters for controlled inflationary plateaus in penumbral monodromic valleys, with an exactly solvable family targeting r ~ 10^{-3} and alpha_s ~ -r/2.
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Reconstructing inflationary features on large scales using genetic algorithm
Genetic algorithm reconstructs single-field inflationary models with features in the scalar power spectrum that fit Planck 2018 CMB data better by Δχ² ≲ -10 and suggest alternative background parameters.
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Imprint of swampland-inspired coupled early dark energy
A swampland-inspired DM-EDE coupling is tested against DESI DR2 BAO data, showing the EDE potential construction affects late-time dark energy constraints.
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Observing Cosmic Reheating with the expanded Simons Observatory
Expanded Simons Observatory could measure reheating temperature and inflaton-gluon coupling to a few percent in QCD-driven warm inflation if r=0.01 primordial gravitational waves are found.
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On Legacy of Starobinsky Inflation
A memorial review of the Starobinsky inflation model that proposes a deformation for primordial black hole production and discusses superstring quantum corrections plus universal reheating.
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Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
The paper reviews cosmological tensions including the H0 and S8 discrepancies and explores new physics models that could explain them.