A Laplace-space representation converts massive single-exchange cosmological correlators in de Sitter into a rapidly convergent series derived from flat-space integrals.
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Inflation: Theory and Observations
Canonical reference. 100% of citing Pith papers cite this work as background.
abstract
Cosmic inflation provides a window to the highest energy densities accessible in nature, far beyond those achievable in any realistic terrestrial experiment. Theoretical insights into the inflationary era and its observational probes may therefore shed unique light on the physical laws underlying our universe. This white paper describes our current theoretical understanding of the inflationary era, with a focus on the statistical properties of primordial fluctuations. In particular, we survey observational targets for three important signatures of inflation: primordial gravitational waves, primordial non-Gaussianity and primordial features. With the requisite advancements in analysis techniques, the tremendous increase in the raw sensitivities of upcoming and planned surveys will translate to leaps in our understanding of the inflationary paradigm and could open new frontiers for cosmology and particle physics. The combination of future theoretical and observational developments therefore offer the potential for a dramatic discovery about the nature of cosmic acceleration in the very early universe and physics on the smallest scales.
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Closed-form mode functions and power spectrum for a two-field inflation model with arbitrary coupling λ and isocurvature mass μ, including the previously difficult strong-coupling regime.
Derives integro-differential boundary equations from bulk locality for scale-breaking cosmological correlators with oscillating heavy-field masses and solves them analytically and numerically to reveal enhanced collider signals.
The double-exchange cosmological correlator is computed in KLF space, yielding a double series over hypergeometric functions that improves on prior four-layer representations.
Laplace transform converts cosmological correlator diagrams into flat-space integrals against kernels, yielding a closed-form rapidly convergent series for the massive single-exchange case valid across the full kinematic domain.
Introduces spectral dispersion bootstrap combining dS spectral decomposition and dispersion relations to compute 3- and 4-point loop correlators with massive scalar and vector exchanges.
Conditioning CAMELS-SAM simulations on the stellar mass function or stellar-to-halo mass relation reduces uncertainty in b_phi by 88-97% for DESI emission line galaxy samples while remaining consistent across galaxy formation variations.
A parity-split IBP system for n-propagator families in de Sitter space is identified, along with a conjecture that dlog-form differential equations extend to dS integrands with Hankel functions, verified for the one-loop bubble.
Chemical potential from a unique dim-5 inflaton–right-handed-neutrino operator softens heavy-mass Boltzmann suppression and amplifies helicity-dependent oscillatory non-Gaussianity from the fermion triangle loop.
Second and third moments of joint weak-lensing, tSZ, and X-ray maps improve primordial non-Gaussianity constraints by a factor of ~2 relative to lensing alone while breaking baryon and foreground degeneracies.
The Coherence Principle supplies a falsifiable prior for Bayesian model selection by converting compatibility with a theory's validated grammar into prior weights via a maximum-entropy exponential controlled by one parameter.
Non-Gaussian primordial fluctuations of a Z2-symmetric spectator scalar trigger a strong first-order electroweak phase transition, with the field serving as cold dark matter and generating a stochastic gravitational wave background in the 10^{-3}-10^{-1} Hz band.
The paper derives a correspondence between boundary terms and field redefinitions for cosmological correlators and classifies non-vanishing boundary contributions in massive-exchange diagrams under dS isometries and broken boosts.
Extends diagrammatic approach for scalar-induced gravitational waves to arbitrary-order local PNG, deriving semi-analytic spectra for energy density, anisotropies, bispectrum and trispectrum up to quartic terms.
Joint power spectrum and bispectrum analysis from future HI intensity mapping surveys improves constraints on primordial feature amplitudes by 30-40% and achieves percent-level precision on oscillation frequencies when combined with CMB measurements.
Inflation dynamically suppresses the renormalization sector, rendering the observable primordial spectrum insensitive to renormalization ambiguities.
A light axion spectator induces post-inflation tachyonic phases that produce a nearly scale-invariant boost to the curvature power spectrum and alter key inflationary observables in a largely potential-independent manner.
Validates redshift-space power spectrum and bispectrum analysis on Abacus-PNG mocks to recover unbiased f_NL constraints for Euclid spectroscopic sample.
Classical and quantum correlation functions of inflationary perturbations diverge exponentially with e-folds when interactions are relevant, even if forced to agree at an intermediate time.
Compares two methods to resolve disagreements and prove positivity of anomalous dimensions for principal series fields coupled to compact scalar operators in de Sitter space.
Systematic re-analysis of Planck PR3 and PR4 CMB datasets finds local fit improvements of up to Δχ² ≈ -15 for certain oscillatory templates but no global significance above 2.6σ after look-elsewhere correction and Bayesian penalties.
Reexamination of Planck CMB data finds a possible spatial-parity-breaking signal consistent with six extra dimensions compactified toroidally at the GUT scale before inflation.
A matter bounce model driven by a scalar field with exponential potential fits Planck 2018 CMB data comparably to inflationary ΛCDM, with the potential slope λ directly setting the scalar spectral index ns.
MUST is a planned 6.5m Stage-V spectroscopic survey telescope targeting 100M+ galaxies and quasars to z~5.5 for large-scale structure cosmology studies.
citing papers explorer
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Massive Cosmological Correlators from Flat Space: a Laplace-Space Approach
A Laplace-space representation converts massive single-exchange cosmological correlators in de Sitter into a rapidly convergent series derived from flat-space integrals.
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Pushing the Primordial Frontier: Exact Linear Solutions in Multifield Inflation
Closed-form mode functions and power spectrum for a two-field inflation model with arbitrary coupling λ and isocurvature mass μ, including the previously difficult strong-coupling regime.
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Every Wrinkle Carries A Memory: An Integro-differential Bootstrap for Features in Cosmological Correlators
Derives integro-differential boundary equations from bulk locality for scale-breaking cosmological correlators with oscillating heavy-field masses and solves them analytically and numerically to reveal enhanced collider signals.
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Cosmological Correlators in KLF and the Double-Exchange
The double-exchange cosmological correlator is computed in KLF space, yielding a double series over hypergeometric functions that improves on prior four-layer representations.
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Laplace Space for Cosmological Correlators
Laplace transform converts cosmological correlator diagrams into flat-space integrals against kernels, yielding a closed-form rapidly convergent series for the massive single-exchange case valid across the full kinematic domain.
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On-Shell Bootstrap of Loop Inflation Correlators with Spectral Dispersion
Introduces spectral dispersion bootstrap combining dS spectral decomposition and dispersion relations to compute 3- and 4-point loop correlators with massive scalar and vector exchanges.
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Informative Priors on Primordial Non-Gaussianity Bias $b_{\phi}$ From Galaxy Formation
Conditioning CAMELS-SAM simulations on the stellar mass function or stellar-to-halo mass relation reduces uncertainty in b_phi by 88-97% for DESI emission line galaxy samples while remaining consistent across galaxy formation variations.
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Loop integrals in de Sitter spacetime: The parity-split IBP system and $\mathrm{d}\log$-form differential equations
A parity-split IBP system for n-propagator families in de Sitter space is identified, along with a conjecture that dlog-form differential equations extend to dS integrands with Hankel functions, verified for the one-loop bubble.
-
Cosmological Collider Signatures from Right-Handed Neutrino Loop
Chemical potential from a unique dim-5 inflaton–right-handed-neutrino operator softens heavy-mass Boltzmann suppression and amplifies helicity-dependent oscillatory non-Gaussianity from the fermion triangle loop.
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Primordial Physics in the Nonlinear Universe: Towards particle constraints using the Weak lensing, Thermal SZ, and X-ray fields
Second and third moments of joint weak-lensing, tSZ, and X-ray maps improve primordial non-Gaussianity constraints by a factor of ~2 relative to lensing alone while breaking baryon and foreground degeneracies.
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The Coherence Principle: A Falsifiable Prior for Model Selection from the Grammar of Theories
The Coherence Principle supplies a falsifiable prior for Bayesian model selection by converting compatibility with a theory's validated grammar into prior weights via a maximum-entropy exponential controlled by one parameter.
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Electroweak First-Order Phase Transition Triggered by Non-Gaussian Fluctuations of a $\mathbb{Z}_2$-Symmetric Spectator Scalar
Non-Gaussian primordial fluctuations of a Z2-symmetric spectator scalar trigger a strong first-order electroweak phase transition, with the field serving as cold dark matter and generating a stochastic gravitational wave background in the 10^{-3}-10^{-1} Hz band.
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On Cosmological Correlators with Boundary Contributions
The paper derives a correspondence between boundary terms and field redefinitions for cosmological correlators and classifies non-vanishing boundary contributions in massive-exchange diagrams under dS isometries and broken boosts.
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Isotropy, anisotropies and non-Gaussianity in the scalar-induced gravitational-wave background: diagrammatic approach for primordial non-Gaussianity up to arbitrary order
Extends diagrammatic approach for scalar-induced gravitational waves to arbitrary-order local PNG, deriving semi-analytic spectra for energy density, anisotropies, bispectrum and trispectrum up to quartic terms.
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Searching for primordial features with radio surveys: synergy between the power spectrum and bispectrum
Joint power spectrum and bispectrum analysis from future HI intensity mapping surveys improves constraints on primordial feature amplitudes by 30-40% and achieves percent-level precision on oscillation frequencies when combined with CMB measurements.
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Renormalization effects fade away during inflation
Inflation dynamically suppresses the renormalization sector, rendering the observable primordial spectrum insensitive to renormalization ambiguities.
-
Tachyonic Encore: A universal shift of inflationary observables
A light axion spectator induces post-inflation tachyonic phases that produce a nearly scale-invariant boost to the curvature power spectrum and alter key inflationary observables in a largely potential-independent manner.
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Euclid preparation: Testing multi-field inflation with galaxy power spectrum and bispectrum
Validates redshift-space power spectrum and bispectrum analysis on Abacus-PNG mocks to recover unbiased f_NL constraints for Euclid spectroscopic sample.
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Classical and quantum evolution of inflationary fluctuations
Classical and quantum correlation functions of inflationary perturbations diverge exponentially with e-folds when interactions are relevant, even if forced to agree at an intermediate time.
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A Compact Story of Positivity in de Sitter
Compares two methods to resolve disagreements and prove positivity of anomalous dimensions for principal series fields coupled to compact scalar operators in de Sitter space.
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Signals from the early Universe: a comprehensive search for primordial features in Planck CMB datasets
Systematic re-analysis of Planck PR3 and PR4 CMB datasets finds local fit improvements of up to Δχ² ≈ -15 for certain oscillatory templates but no global significance above 2.6σ after look-elsewhere correction and Bayesian penalties.
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Probing String-Theory-Inspired Topologies of the Early Universe through CMB Temperature and Polarization Anisotropies
Reexamination of Planck CMB data finds a possible spatial-parity-breaking signal consistent with six extra dimensions compactified toroidally at the GUT scale before inflation.
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Single field matter bounce with dark energy era: comparison with CMB Planck 2018 data and best fit parameters
A matter bounce model driven by a scalar field with exponential potential fits Planck 2018 CMB data comparably to inflationary ΛCDM, with the potential slope λ directly setting the scalar spectral index ns.
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MUltiplexed Survey Telescope (MUST) Science White Paper I: Overview of Large-Scale Structure Cosmology in the Era of Stage-V Spectroscopic Surveys
MUST is a planned 6.5m Stage-V spectroscopic survey telescope targeting 100M+ galaxies and quasars to z~5.5 for large-scale structure cosmology studies.
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Beyond {\Lambda}CDM with the SKA Observatory -- II: Unveiling the Secrets of the Early Universe
Updated SKAO-AA4 forecasts show multi-tracer HI+galaxy analyses can reach σ(f_local_NL)≲1 and improve αs bounds by tens of percent when combined with future CMB, while foregrounds and GR light-cone effects remain the main systematics.