A Laplace-space representation converts massive single-exchange cosmological correlators in de Sitter into a rapidly convergent series derived from flat-space integrals.
Cosmological Collider in the Grassmannian
4 Pith papers cite this work. Polarity classification is still indexing.
4
Pith papers citing it
abstract
We revisit the computation of four-point wavefunction coefficients and correlators for external conformally coupled scalars exchanging a particle of generic mass and spin. Much of the phenomenology of cosmological collider physics in the near-de Sitter limit follows from these functions. Computing them in detail is a central challenge in the cosmological bootstrap. Using the cosmological Grassmannian, we write these objects in closed form using hypergeometric functions and Legendre polynomials. We achieve this by writing the standard bootstrap differential equation using the Pl\"ucker coordinates of the Grassmannian, and using the basis of Mandelstam invariants. The exchange in the s-channel can be written in terms of a hypergeometric function of the S Mandelstam, while the spin information appears as an overall Legendre polynomial factor that also depends on the other Mandelstams. We fix the boundary conditions by first demanding the absence of unphysical singularities, and, for correlators, by further matching to a kinematic limit in momentum space. Our formulae in Grassmannian space are much simpler than their counterparts in momentum space, demonstrating another useful application of the Grassmannian as a kinematic space for cosmology.
years
2026 4verdicts
UNVERDICTED 4representative citing papers
Introduces a bridge transformation on the orthogonal Grassmannian to produce an algebraic recursion for cosmological correlators and identifies the stripped four-gluon correlator as the canonical form of a rectangle in positive geometry.
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.
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.
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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A Cosmological BCFW Bridge and Its Canonical Geometry
Introduces a bridge transformation on the orthogonal Grassmannian to produce an algebraic recursion for cosmological correlators and identifies the stripped four-gluon correlator as the canonical form of a rectangle in positive geometry.
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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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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.