The two-loop correction to the diffusion coefficient in stochastic inflation is computed for the first time via composite-operator renormalisation and matching in SdSET.
dynamical mass
4 Pith papers cite this work. Polarity classification is still indexing.
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abstract
We consider the perturbative treatment of the minimally coupled, massless, self-interacting scalar field in Euclidean de Sitter space. Generalizing work of Rajaraman, we obtain the dynamical mass m^2 \propto sqrt{lambda} H^2 of the scalar for non-vanishing Lagrangian masses and the first perturbative quantum correction in the massless case. We develop the rules of a systematic perturbative expansion, which treats the zero-mode non-perturbatively, and goes in powers of sqrt{lambda}. The infrared divergences are self-regulated by the zero-mode dynamics. Thus, in Euclidean de Sitter space the interacting, massless scalar field is just as well-defined as the massive field. We then show that the dynamical mass can be recovered from the diagrammatic expansion of the self-energy and a consistent solution of the Schwinger-Dyson equation, but requires the summation of a divergent series of loop diagrams of arbitrarily high order. Finally, we note that the value of the long-wavelength mode two-point function in Euclidean de Sitter space agrees at leading order with the stochastic treatment in Lorentzian de Sitter space, in any number of dimensions.
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background 2representative citing papers
A generalized Fokker-Planck equation for stochastic inflation is derived from a Polchinski-type renormalization group flow on the density matrix, incorporating dissipative and diffusive corrections beyond the leading order.
Two-loop Yukawa corrections in de Sitter yield ⟨ϕ²⟩ ~ ln⁴a at late times, with a resummed expression that is bounded, decreases with larger Yukawa coupling, and implies a growing dynamical scalar mass.
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.
citing papers explorer
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Quantum correction to the diffusion term in stochastic inflation from composite-operator matching in Soft de Sitter Effective Theory
The two-loop correction to the diffusion coefficient in stochastic inflation is computed for the first time via composite-operator renormalisation and matching in SdSET.
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Stochastic inflation from a non-equilibrium renormalization group
A generalized Fokker-Planck equation for stochastic inflation is derived from a Polchinski-type renormalization group flow on the density matrix, incorporating dissipative and diffusive corrections beyond the leading order.
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Yukawa scalar self energy at two loop and $\langle \phi^2 \rangle$ in the inflationary de Sitter spacetime
Two-loop Yukawa corrections in de Sitter yield ⟨ϕ²⟩ ~ ln⁴a at late times, with a resummed expression that is bounded, decreases with larger Yukawa coupling, and implies a growing dynamical scalar mass.
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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.