Different dimensional regularization schemes agree with each other and with unitarity; new analytic eta regulators simplify the work and fix the imaginary part of one-loop coefficients by the logarithmic running of the real part under scale invariance and Bunch-Davies conditions.
Di Pietro, V
6 Pith papers cite this work. Polarity classification is still indexing.
6
Pith papers citing it
abstract
We study finite-coupling effects of QFT on a rigid de Sitter (dS) background taking the $O(N)$ vector model at large $N$ as a solvable example. Extending standard large $N$ techniques to the dS background, we analyze the phase structure and late-time four-point functions. Explicit computations reveal that the spontaneous breaking of continuous symmetries is prohibited due to strong IR effects, akin to flat two-dimensional space. Resumming loop diagrams, we compute the late-time four-point functions of vector fields at large $N$, demonstrating that their spectral density is meromorphic in the spectral plane and positive along the principal series. These results offer highly nontrivial checks of unitarity and analyticity for cosmological correlators.
fields
hep-th 6representative citing papers
A deformed Calogero model accommodates unitary principal series states of sl(2,R) via operator domain changes, preserving unitarity and invariance while altering integrability, with solutions for N=2 and 3.
Standard SdSET power counting fails for classically conformal φ⁴; leading superhorizon modes must be read from the two-loop anomalous dimension of the two-point function.
Quantization of axions on dS_D yields Hilbert space H = L^2(S^1) ⊗ F with zero-mode U(1) charge, producing non-dS-invariant charged sectors and Hadamard Wightman functions that become asymptotically invariant.
Explicit one-loop computation shows the constraint effective potential for scalars in de Sitter is free of infrared problems and supports its use in stochastic Starobinsky-Yokoyama inflation.
Develops a Functorial QFT approach and applies it to analyze the O(N) model in AdS, focusing on crossed-channel diagram contributions to conformal block decomposition in the non-singlet sector.
citing papers explorer
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Unitary and Analytic Renormalisation of Cosmological Correlators
Different dimensional regularization schemes agree with each other and with unitarity; new analytic eta regulators simplify the work and fix the imaginary part of one-loop coefficients by the logarithmic running of the real part under scale invariance and Bunch-Davies conditions.
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Medicine show: A Calogero model with principal series states
A deformed Calogero model accommodates unitary principal series states of sl(2,R) via operator domain changes, preserving unitarity and invariance while altering integrability, with solutions for N=2 and 3.
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Classical conformal invariance and superhorizon dynamics in de Sitter
Standard SdSET power counting fails for classically conformal φ⁴; leading superhorizon modes must be read from the two-loop anomalous dimension of the two-point function.
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Axions on de Sitter space
Quantization of axions on dS_D yields Hilbert space H = L^2(S^1) ⊗ F with zero-mode U(1) charge, producing non-dS-invariant charged sectors and Hadamard Wightman functions that become asymptotically invariant.
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Scalar field effective potentials in de Sitter spacetime
Explicit one-loop computation shows the constraint effective potential for scalars in de Sitter is free of infrared problems and supports its use in stochastic Starobinsky-Yokoyama inflation.
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Strongly Coupled Quantum Field Theory in Anti-de Sitter Spacetime
Develops a Functorial QFT approach and applies it to analyze the O(N) model in AdS, focusing on crossed-channel diagram contributions to conformal block decomposition in the non-singlet sector.