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We propose a new mechanism to generate density perturbations in inflationary models. Spatial fluctuations in the decay rate of the inflaton field to ordinary matter lead to fluctuations in the reheating temperature. We argue that in most…

Astrophysics · Physics 2009-11-07 Gia Dvali , Andrei Gruzinov , Matias Zaldarriaga

Curvature perturbations with short wavelengths exit the Hubble horizon when the universe may contain a thermal plasma in addition to an inflaton field that drives its expansion. We solve the corresponding fluctuation-dissipation dynamics at…

High Energy Physics - Phenomenology · Physics 2026-01-05 M. Laine , S. Procacci , A. Rogelj

We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the…

Astrophysics · Physics 2009-11-10 F. J. Cao , H. J. de Vega , N. G. Sanchez

We consider a simple system consisting of matter, radiation and vacuum components to model the impact of thermal inflation on the evolution of primordial perturbations. The vacuum energy magnifies the primordial modes entering the horizon…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-11 Jeong-Myeong Bae , Sungwook E. Hong , Heeseung Zoe

In this paper, we study a problem of controlling cooling facilities and computational equipments for energy-efficient operations of data centers. Although a plethora of approaches have been proposed in previous literatures, there is a lack…

Optimization and Control · Mathematics 2019-03-19 Masaki Ogura , Jianxiong Wan , Shoji Kasahara

In this paper, we propose a model predictive control (MPC) method for real-time intervention of spreading processes, such as epidemics and wildfire, over large-scale networks. The goal is to allocate budgeted resources each time step to…

Optimization and Control · Mathematics 2022-10-31 Ruigang Wang , Armaghan Zafar , Ian R. Manchester

Output regulation is the problem of finding a control input to asymptotically track reference trajectories and reject disturbances. This can be addressed by using the internal model principle to embed a model of the disturbance in the…

Systems and Control · Electrical Eng. & Systems 2026-04-02 Felix Brändle , Frank Allgöwer

Markov Chain Monte Carlo (MCMC) algorithms are essential tools in computational statistics for sampling from unnormalised probability distributions, but can be fragile when targeting high-dimensional, multimodal, or complex target…

We predict the development and propagation of the fluctuations in a perturbed ideally-expanded air jet. A non-propagating harmonic perturbation in the density, axial velocity, and pressure is introduced at the inflow with different…

Fluid Dynamics · Physics 2025-01-16 Osama A. Marzouk

Model Predictive Control (MPC) is widely used to operate safety-critical infrastructure by predicting future trajectories and optimizing control actions. However, nonlinear dynamics, hard safety constraints, and numerical optimization often…

Artificial Intelligence · Computer Science 2026-05-12 Ramesh Arvind Naagarajan , Zühal Wagner , Stefan Streif

We present a stochastic model predictive control (MPC) method for linear discrete-time systems subject to possibly unbounded and correlated additive stochastic disturbance sequences. Chance constraints are treated in analogy to robust MPC…

Systems and Control · Computer Science 2019-01-23 Lukas Hewing , Kim P. Wabersich , Melanie N. Zeilinger

A novel centralized model predictive control (MPC) is proposed for comfort and energy management in a residential building. The residential setup used here is equipped with a photovoltaic (PV) solar system and a stationary home battery…

Systems and Control · Electrical Eng. & Systems 2019-12-17 Sayani Seal , Benoit Boulet , Vahid Raissi Dehkordi

We present a robust adaptive model predictive control (MPC) framework for nonlinear continuous-time systems with bounded parametric uncertainty and additive disturbance. We utilize general control contraction metrics (CCMs) to parameterize…

Systems and Control · Electrical Eng. & Systems 2023-07-12 András Sasfi , Melanie N. Zeilinger , Johannes Köhler

This paper presents a stochastic model predictive controller (SMPC) for linear time-invariant systems in the presence of additive disturbances. The distribution of the disturbance is unknown and is assumed to have a bounded support. A…

Systems and Control · Electrical Eng. & Systems 2022-10-03 Hotae Lee , Monimoy Bujarbaruah , Francesco Borrelli

A thorough MCMC analysis of any inflationary model against the current cosmological data is essential for assessing the validity of such a model as a viable inflationary model. Warm Inflation, producing both thermal and quantum…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-29 Umang Kumar , Suratna Das

We develop a non-linear framework for describing long-wavelength perturbations in multiple-field inflation. The basic variables describing inhomogeneities are defined in a non-perturbative manner, are invariant under changes of time slicing…

Astrophysics · Physics 2009-11-11 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

The nonequilibrium dynamics of quantum fields is studied in inflationary cosmology, with particular emphasis on applications to the problem of post-inflation reheating. The Schwinger-Keldysh closed-time-path (CTP) formalism is utilized…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stephen A. Ramsey

Reconstructing a thermal model capable of efficiently simulating the behavior of a spacecraft from sparse and localized temperature measurements remains a challenging task. To address this, we introduce a physically-constrained calibration…

Numerical Analysis · Mathematics 2026-05-28 Luca Sosta , Carlo Ciancarelli , Leonardo Marini , Stefano Pagani , Francesco Regazzoni , Nicola Parolini

Due to their transient nature, clouds represent anomalies relative to the underlying landscape of interest. Hence, the challenge of cloud identification can be considered a specific case in the more general problem of anomaly detection. The…

Geophysics · Physics 2024-01-15 Christopher Small , Daniel Sousa

Model predictive control (MPC) can provide significant energy cost savings in building operations in the form of energy-efficient control with better occupant comfort, lower peak demand charges, and risk-free participation in demand…

Systems and Control · Electrical Eng. & Systems 2020-05-05 Achin Jain , Francesco Smarra , Enrico Reticcioli , Alessandro D'Innocenzo , Manfred Morari