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Related papers: Reheating-volume measure for random-walk inflation

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In this paper we study the reheating constraints on inflationary models considering perturbatively decaying inflaton. Important difference with the existing analysis is the inclusion of explicit decaying dynamics of inflaton during…

High Energy Physics - Theory · Physics 2020-11-05 Debaprasad Maity

In a previous paper, two of the authors presented a "regulated" picture of eternal inflation. This picture both suggested and drew support from a conjectured discontinuity in the amplitude for tunneling from positive to negative vacuum…

High Energy Physics - Theory · Physics 2009-11-11 A. Aguirre , T. Banks , M. Johnson

BICEP2 measurement of primordial tensor modes in CMB suggests that cosmological inflation is due to a slowly rolling inflaton taking trans-Planckian values and provides further experimental evidence for the absence of large $M_{\rm P}$…

High Energy Physics - Phenomenology · Physics 2014-12-10 Antonio Racioppi

The purpose of this paper is to implement a random death process into a persistent random walk model which produces subballistic superdiffusion (L\'{e}vy walk). We develop a Markovian model of cell motility with the extra residence variable…

Statistical Mechanics · Physics 2015-05-20 Sergei Fedotov , Abby Tan , Andrey Zubarev

We investigate the modifications to inflationary observables that arise when adopting an $\alpha$-vacuum instead of the standard Bunch--Davies vacuum for quantum fluctuations during inflation. Within the Starobinsky inflationary model, we…

General Relativity and Quantum Cosmology · Physics 2026-05-11 Melo Wood-Saanaoui , Rudnei O. Ramos , Arjun Berera

The availability of data on economic uncertainty sparked a lot of interest in models that can timely quantify episodes of international spillovers of uncertainty. This challenging task involves trading off estimation accuracy for more…

General Economics · Economics 2023-02-07 Niels Gillmann , Ostap Okhrin

Random walk in random environment (RWRE) is a fundamental model of statistical mechanics, describing the movement of a particle in a highly disordered and inhomogeneous medium as a random walk with random jump probabilities. It has been…

Probability · Mathematics 2013-09-11 Alexander Drewitz , Alejandro F. Ramírez

If in a finite universe, the tree-level vacuum is a symmetric superposition of coherent states, in each of which the inflaton field assumes a different, energy-minimizing mean value (vev), then the resulting energy is positive and decreases…

General Relativity and Quantum Cosmology · Physics 2007-05-24 Kevin Cahill

I summarize the arguments that strongly suggest that our universe is the product of inflation. The mechanisms that lead to eternal inflation in both new and chaotic models are described. Although the infinity of pocket universes produced by…

High Energy Physics - Theory · Physics 2008-11-26 Alan H. Guth

Continuous-time random walks are a well suited tool for the description of market behaviour at the smallest scale: the tick-to-tick evolution. We will apply this kind of market model to the valuation of perpetual American options:…

Pricing of Securities · Quantitative Finance 2008-12-02 Miquel Montero

The possibility that the non-minimal coupling inflation could be eternal is investigated. We calculate the quantum fluctuation of the inflaton in a Hubble time and find that it has the same value as in the minimal case in the slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Chao-Jun Feng , Xin-Zhou Li

Variational inference has had great success in scaling approximate Bayesian inference to big data by exploiting mini-batch training. To date, however, this strategy has been most applicable to models of independent data. We propose an…

Machine Learning · Statistics 2021-05-19 Tom Ryder , Dennis Prangle , Andrew Golightly , Isaac Matthews

In this work, we develop a probabilistic estimator for the voltage-to-current map arising in electrical impedance tomography. This novel so-called partially reflecting random walk on spheres estimator enables Monte Carlo methods to compute…

Numerical Analysis · Mathematics 2015-02-17 Sylvain Maire , Martin Simon

The field of risk theory has traditionally focused on ruin-related quantities. In particular, the socalled Expected Discounted Penalty Function has been the object of a thorough study over the years. Although interesting in their own right,…

Risk Management · Quantitative Finance 2014-06-27 Zied Ben-Salah , Hélène Guérin , Manuel Morales , Hassan Omidi Firouzi

Time-varying parameters (TVPs) models are frequently used in economics to capture structural change. I highlight a rather underutilized fact -- that these are actually ridge regressions. Instantly, this makes computations, tuning, and…

Econometrics · Economics 2024-11-18 Philippe Goulet Coulombe

The temperature at the end of reheating and the length of this cosmological phase can be bound to the inflationary observables if one considers the cosmological evolution from the time of Hubble crossing until today. There are many examples…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Rodolfo C. de Freitas , Sergio V. B. Gonçalves

Starting from a continuous time random walk (CTRW) model of particles that may evanesce as they walk, our goal is to arrive at macroscopic integro-differential equations for the probability density for a particle to be found at point r at…

Statistical Mechanics · Physics 2015-05-14 E. Abad , S. B. Yuste , Katja Lindenberg

Changes in extreme weather may produce some of the largest societal impacts of anthropogenic climate change. However, it is intrinsically difficult to estimate changes in extreme events from the short observational record. In this work we…

The topic of this talk is a new inflationary model in the context of Type IIB string compactifications called Loop Blow-Up Inflation, presented in arXiv:2403.04831. The original Blow-Up Inflation model, whose potential was purely…

High Energy Physics - Theory · Physics 2025-02-24 Luca Brunelli

The vacuum $R^2$ model is known to generate a quasi-de Sitter evolution for inflation, using solely the slow-roll assumptions. Using standard reconstruction techniques, we demonstrate that the $f(R)$ gravity which actually realizes the…

General Relativity and Quantum Cosmology · Physics 2022-01-05 S. D. Odintsov , V. K. Oikonomou