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We explore within the context of brane cosmology whether it is possible to obtain both early inflation and accelerated expansion during the present epoch through the dynamics of the same scalar field in an exponential potential.…

Astrophysics · Physics 2009-11-06 A. S. Majumdar

Generalized linear mixed models are powerful tools for analyzing clustered data, where the unknown parameters are classically (and most commonly) estimated by the maximum likelihood and restricted maximum likelihood procedures. However,…

Statistics Theory · Mathematics 2023-03-23 Andrea M. Bratsberg , Magne Thoresen , Abhik Ghosh

The growing availability of network data and of scientific interest in distributed systems has led to the rapid development of statistical models of network structure. Typically, however, these are models for the entire network, while the…

Statistics Theory · Mathematics 2022-03-18 Cosma Rohilla Shalizi , Alessandro Rinaldo

We investigate the effects of finite sky coverage on the spectral resolution $\Delta\ell$ in the estimation of the CMBR angular power spectrum $C^{\ell}$. A method is developed for obtaining quasi-independent estimates of the power…

Astrophysics · Physics 2015-06-24 M. P. Hobson , Joao Magueijo

With the tracking condition, the stability of quintessence solutions are examined. It is found that there is only one physically relevant fixed point for the system generically. Two specific examples of quintessence potentials are worked…

General Relativity and Quantum Cosmology · Physics 2013-12-11 Nandan Roy , narayan Banerjee

We prove an exponential estimate for the asymptotics of Bergman kernels of a positive line bundle under hypotheses of bounded geometry. We give further Bergman kernel proofs of complex geometry results, such as separation of points,…

Differential Geometry · Mathematics 2015-09-09 Xiaonan Ma , George Marinescu

In quintessence scalar field theories, the presence of scaling solutions are important during the radiation and matter epoch due to having their attractor character. Usually, it is assumed that the initial conditions of the quintessence…

General Relativity and Quantum Cosmology · Physics 2020-06-24 Jaume Haro , Jaume Amorós , Supriya Pan

Kernel methods in Quantum Machine Learning (QML) have recently gained significant attention as a potential candidate for achieving a quantum advantage in data analysis. Among other attractive properties, when training a kernel-based model…

Quantum Physics · Physics 2024-04-16 Supanut Thanasilp , Samson Wang , M. Cerezo , Zoë Holmes

An exponential behavior at all times is derived for a solvable dynamical model in the weak-coupling, macroscopic limit. Some implications for the quantum measurement problem are discussed, in particular in connection with dissipation.

High Energy Physics - Theory · Physics 2009-10-28 Hiromichi Nakazato , Mikio Namiki , Saverio Pascazio

We use a dynamical systems approach to study thawing quintessence models, using a multi-parameter extension of the exponential potential which can approximate the form of typical thawing potentials. We impose observational constraints using…

Astrophysics · Physics 2009-07-13 Timothy G Clemson , Andrew R Liddle

We first study dark energy models with a minimally-coupled scalar field and exponential potentials, admitting exact solutions for the cosmological equations: actually, it turns out that for this class of potentials the Einstein field…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Ester Piedipalumbo , Paolo Scudellaro , Giampiero Esposito , Claudio Rubano

This paper proposes two phenomenological quintessence potentials with parameters fitted to the presently observed ratio $\rat$ of smooth energy to clustered mass and limits on the equation of state parameter $w_Q(a)=P/\rhoq$, for which the…

Astrophysics · Physics 2015-06-24 S. A. Bludman

In a recently developed quadrature method (quadrature by expansion or QBX), it was demonstrated that weakly singular or singular layer potentials can be evaluated rapidly and accurately on surface by making use of local expansions about…

Numerical Analysis · Mathematics 2013-04-24 Charles L. Epstein , Leslie Greengard , Andreas Klöckner

The properties of quintessence are examined through the study of the variation of the electromagnetic coupling. We consider two simple quintessence models with a modified exponential potential and study the parameter space constraints…

Astrophysics · Physics 2010-01-05 M. C. Bento , R. Gonzalez Felipe

Consistency relations between growth of structure and expansion history observables exist for any physical explanation of cosmic acceleration, be it a cosmological constant, scalar field quintessence, or a general component of dark energy…

Astrophysics · Physics 2010-04-15 Michael J. Mortonson , Wayne Hu , Dragan Huterer

Exponential families are the workhorses of parametric modelling theory. One reason for their popularity is their associated inference theory, which is very clean, both from a theoretical and a computational point of view. One way in which…

Statistics Theory · Mathematics 2007-09-14 Karim Anaya-Izquierdo , Paul Marriott

We show that when a suitable entanglement generating unitary operator depending on a parameter is applied on N qubits in parallel, and an appropriate observable is measured, a precision of order 2 raised to the power (-N) in estimating the…

Quantum Physics · Physics 2013-05-29 S. M. Roy , Samuel L. Braunstein

The 2015 Planck data release tightened the region of the allowed inflationary models. Inflationary models with convex potentials have now been ruled out since they produce a large tensor to scalar ratio. Meanwhile the same data offers…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Eleonora Di Valentino , Laura Mersini-Houghton

We extend results on robust exponential mixing for geometric Lorenz attractors, with a dense orbit and a unique singularity, to singular-hyperbolic attracting sets with any number of (either Lorenz- or non-Lorenz-like) singularities and…

Dynamical Systems · Mathematics 2023-02-06 Vitor Araujo , Edvan Trindade

We consider nonlinear model predictive control (MPC) schemes without stabilizing terminal conditions, where the model used in the optimization step is generated based on input-output data only. We establish exponential stability for…

Optimization and Control · Mathematics 2026-05-27 Lea Bold , Irene Schimperna , Karl Worthmann , Johannes Köhler