Stochastic inflation with quantum and thermal noise

Haba, Z.

doi:10.1140/epjc/s10052-018-6078-4

Cited by 6 publications

(3 citation statements)

References 50 publications

(108 reference statements)

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“…∂ t W is an independent Gaussian stochastic process with the same covariance (Equation ( 8)). Equation ( 1) with quantum and thermal noise is discussed in [21,22,23].…”

Section: Stochastic Equations For Slow-roll Inflationmentioning

confidence: 99%

Semi-classical Einstein equations:descend to the ground state

Haba

2020

Preprint

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The time-dependent cosmological term arises from the energy-momentum tensor calculated in a state different from the ground state. We discuss the expectation value of the energy-momentum tensor on the rhs of Einstein equations in various (approximate) quantum pure as well as mixed states. We apply the classical slow-roll field evolution as well as the Starobinsky and warm inflation stochastic equations in order to calculate the expectation value. We show that in the state concentrated at the local maximum of the double-well potential the expectation value is decreasing exponentially. We confirm the descend of the expectation value in the stochastic inflation model. We calculate the cosmological constant Λ at large time as the expectation value of the energy density with respect to the stationary probability distribution. We show that Λ ≃ γ 4 3 where γ is the thermal dissipation rate.

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“…∂ t W is an independent Gaussian stochastic process with the same covariance (Equation ( 8)). Equation ( 1) with quantum and thermal noise is discussed in [21,22,23].…”

Section: Stochastic Equations For Slow-roll Inflationmentioning

confidence: 99%

Semi-classical Einstein equations:descend to the ground state

Haba

2020

Preprint

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“…This is a long wave approximation which neglects the second-order derivatives in equations of motion and first-order derivatives in the energy-momentum tensor. The noise in the stochastic equation consists of two independent parts: the quantum noise of Starobinsky [18] and Vilenkin [20] and the thermal noise describing thermal fluctuations [19,[21][22][23]. We consider Einstein equations with the expectation value of the energy-momentum tensor in a quantum state ψ on the rhs of these equations.…”

Section: Introductionmentioning

confidence: 99%

“…In the next step, we are interested in the expectation value in the non-perturbative thermal quantum state. According to the authors of [18,19,22,23], in a slow roll approximation, the field evolution in such a quantum state can be obtained as a solution of a stochastic equation with quantum and thermal noise. We discuss approximate solutions of such equations.…”

Section: Introductionmentioning

confidence: 99%

Semi-Classical Einstein Equations: Descend to the Ground State

Haba

2020

Universe

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The time-dependent cosmological term arises from the energy-momentum tensor calculated in a state different from the ground state. We discuss the expectation value of the energy-momentum tensor on the right hand side of Einstein equations in various (approximate) quantum pure as well as mixed states. We apply the classical slow-roll field evolution as well as the Starobinsky and warm inflation stochastic equations in order to calculate the expectation value. We show that, in the state concentrated at the local maximum of the double-well potential, the expectation value is decreasing exponentially. We confirm the descent of the expectation value in the stochastic inflation model. We calculate the cosmological constant Λ at large time as the expectation value of the energy density with respect to the stationary probability distribution. We show that Λ ≃ γ 4 3 where γ is the thermal dissipation rate.

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Energy stored on a cosmological horizon and its thermodynamic fluctuations in holographic equipartition law

Komatsu

2022

Phys. Rev. D

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Stochastic inflation with quantum and thermal noise

Abstract: We add a thermal noise to Starobinsky equation of slow roll inflation. We calculate the number of e-folds of the stochastic system. The power spectrum and the spectral index are evaluated from the fluctuations of the e-folds using an expansion in the quantum and thermal noise terms.

Cited by 6 publications

References 50 publications

Semi-classical Einstein equations:descend to the ground state

Semi-classical Einstein equations:descend to the ground state

Semi-Classical Einstein Equations: Descend to the Ground State

Energy stored on a cosmological horizon and its thermodynamic fluctuations in holographic equipartition law

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