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A de Sitter S-matrix from amputated cosmological correlators

12 Pith papers cite this work. Polarity classification is still indexing.

12 Pith papers citing it
abstract

Extending scattering to states with unphysical mass values (particles ``off their mass shell'') has been instrumental in developing modern amplitude technology for Minkowski spacetime. Here, we study the off-shell correlators which underpin the recently proposed S-matrix for scattering on de Sitter spacetime. By labelling each particle with both a spatial momentum and an independent ``energy'' variable (the de Sitter analogue of a 4-momentum), we find that the practical computation of these correlators is greatly simplified. This allows us to derive compact expressions for all 3- and 4-particle S-matrices at tree-level for scalar fields coupled through any derivative interactions. As on Minkowski, we find that the 3-particle and exchange part of the 4-particle S-matrices are unique (up to crossing). The remaining contact part of the 4-particle S-matrix is an analytic function of just two differential operators, which become the usual Mandelstam variables in the Minkowski limit. Finally, we introduce a spectral decomposition for the tree-level exchange of a heavy field responsible for a cosmological collider signal. Once projected onto physical mass eigenstates, these S-matrix elements encode the statistical properties of the early inflationary perturbations.

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hep-th 12

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2026 9 2025 3

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representative citing papers

Kontorovich-Lebedev-Fourier Space for de Sitter Correlators

hep-th · 2026-04-16 · unverdicted · novelty 8.0

A Kontorovich-Lebedev-Fourier space is built for (d+1)-dimensional de Sitter correlators from the Casimir operator of SO(1,d+1), producing rational propagators and Feynman rules that turn tree and loop diagrams into spectral integrals and orthogonality relations.

De Sitter Momentum Space

hep-th · 2026-01-21 · unverdicted · novelty 8.0

A Kontorovitch-Lebedev-Fourier momentum space is constructed for de Sitter QFT where the dS frequency labels unitary representations, making equations algebraic and propagators simple like in flat space.

Cosmological Correlators in KLF and the Double-Exchange

hep-th · 2026-07-06 · conditional · novelty 7.0

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 Space for Cosmological Correlators

hep-th · 2026-06-25 · unverdicted · novelty 7.0

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.

Cosmological Collider in the Grassmannian

hep-th · 2026-05-20 · unverdicted · novelty 7.0 · 2 refs

Four-point wavefunction coefficients for external conformally coupled scalars exchanging a particle of generic mass and spin are expressed in closed form as hypergeometric functions of Mandelstam invariants times Legendre polynomials in the cosmological Grassmannian.

Differential Equations for Massive Correlators

hep-th · 2026-04-09 · unverdicted · novelty 7.0

A graph-tubing combinatorial framework governs the first-order differential equations obeyed by master integrals for massive cosmological correlators in de Sitter space.

Correlators are simpler than wavefunctions

hep-th · 2025-12-29 · conditional · novelty 6.0

Equal-time correlators are simpler than wavefunctions because they come from full-spacetime integrals; this implies fewer poles, cleaner factorization, and a systematic pole expansion whose first subleading term vanishes.

A Compact Story of Positivity in de Sitter

hep-th · 2025-08-11 · unverdicted · novelty 5.0

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.

citing papers explorer

Showing 12 of 12 citing papers.

  • Massive Cosmological Correlators from Flat Space: a Laplace-Space Approach hep-th · 2026-06-25 · unverdicted · none · ref 41

    A Laplace-space representation converts massive single-exchange cosmological correlators in de Sitter into a rapidly convergent series derived from flat-space integrals.

  • Kontorovich-Lebedev-Fourier Space for de Sitter Correlators hep-th · 2026-04-16 · unverdicted · none · ref 128

    A Kontorovich-Lebedev-Fourier space is built for (d+1)-dimensional de Sitter correlators from the Casimir operator of SO(1,d+1), producing rational propagators and Feynman rules that turn tree and loop diagrams into spectral integrals and orthogonality relations.

  • De Sitter Momentum Space hep-th · 2026-01-21 · unverdicted · none · ref 6

    A Kontorovitch-Lebedev-Fourier momentum space is constructed for de Sitter QFT where the dS frequency labels unitary representations, making equations algebraic and propagators simple like in flat space.

  • Every Wrinkle Carries A Memory: An Integro-differential Bootstrap for Features in Cosmological Correlators hep-th · 2025-10-31 · unverdicted · none · ref 26

    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.

  • Cosmological Correlators in KLF and the Double-Exchange hep-th · 2026-07-06 · conditional · none · ref 43 · internal anchor

    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 Space for Cosmological Correlators hep-th · 2026-06-25 · unverdicted · none · ref 20

    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.

  • Cosmological Collider in the Grassmannian hep-th · 2026-05-20 · unverdicted · none · ref 4 · 2 links

    Four-point wavefunction coefficients for external conformally coupled scalars exchanging a particle of generic mass and spin are expressed in closed form as hypergeometric functions of Mandelstam invariants times Legendre polynomials in the cosmological Grassmannian.

  • Differential Equations for Massive Correlators hep-th · 2026-04-09 · unverdicted · none · ref 33

    A graph-tubing combinatorial framework governs the first-order differential equations obeyed by master integrals for massive cosmological correlators in de Sitter space.

  • Unitarity, Recursion and Soft Limits in (EA)dS through Dressing hep-th · 2026-06-03 · conditional · none · ref 15

    Structural properties of (E)AdS cosmological correlators—cutting rules, tree theorems, BCFW recursion, and soft limits—are obtained by dressing flat-space amplitudes with auxiliary propagators.

  • Correlators are simpler than wavefunctions hep-th · 2025-12-29 · conditional · none · ref 17

    Equal-time correlators are simpler than wavefunctions because they come from full-spacetime integrals; this implies fewer poles, cleaner factorization, and a systematic pole expansion whose first subleading term vanishes.

  • Cancellation of one-parameter graviton gauge dependence in the effective scalar field equation in de Sitter hep-th · 2026-02-08 · unverdicted · none · ref 44

    Gauge dependence cancels in the one-loop effective scalar equation in de Sitter when all diagram contributions including external mode corrections are collected.

  • A Compact Story of Positivity in de Sitter hep-th · 2025-08-11 · unverdicted · none · ref 57

    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.