English
Related papers

Related papers: Parameter estimation for an expanding universe

200 papers

In quantum theory, the inescapable interaction between a system and its surroundings would lead to a loss of coherence and leakage of information into the environment. An effective approach to retain the quantum characteristics of the…

Quantum Physics · Physics 2025-08-29 Guohui Dong , Yao Yao

We give improved estimates for the non-perturbative parameters appearing in the heavy quark expansion for inclusive decays. While the parameters appearing in low orders of this expansion can be extracted from data, the number of parameters…

High Energy Physics - Phenomenology · Physics 2014-12-16 Johannes Heinonen , Thomas Mannel

Quantum-enhanced (i.e., higher performance by quantum effects than any classical methods) mean value estimation of observables is a fundamental task in various quantum technologies; in particular, it is an essential subroutine in quantum…

Quantum Physics · Physics 2024-09-11 Kaito Wada , Kazuma Fukuchi , Naoki Yamamoto

We explore precision in a measurement process incorporating pure probe states, unitary dynamics and complete measurements via a simple formalism. The concept of `information complement' is introduced. It undermines measurement precision and…

Quantum Physics · Physics 2010-02-17 Gabriel A. Durkin

We study the optimal way to estimate the quantum expectation value of a physical observable when a finite number of copies of a quantum pure state are presented. The optimal estimation is determined by minimizing the squared error averaged…

Quantum Physics · Physics 2009-11-11 A. Hayashi , M. Horibe , T. Hashimoto

Two different realistic $F(R)$ modified gravity models are considered in the framework of the Friedmann-Lemetre-Robertson-Walker universe. The parameters of these two models are adjusted to reach coherence with the most recent and accurate…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Antonio Jesús López-Revelles

A new approach to extraction of quantum vacuum energy, in the context of the accelerated expansion, is proposed, and it is shown that experimentally realistic orders of values can be derived. The idea has been implemented in the framework…

Astrophysics · Physics 2009-06-17 Bogusław Broda , Michał Szanecki

Assuming a flat Friedmann-Robertson-Walker cosmology with a single perfect fluid, we propose a pressure-density ratio that evolves as a specific universal function of the scale parameter. We show that such a ratio can indeed be consistent…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Golam Mortuza Hossain , Parthasarathi Majumdar

The energy-time uncertainty relation puts a fundamental limit on the precision of radars and lidars for the estimation of range and velocity. The precision in the estimation of the range (through the time of arrival) and the velocity…

Quantum Physics · Physics 2021-07-14 Zixin Huang , Cosmo Lupo , Pieter Kok

The maximum size of a cosmic structure is given by the maximum turnaround radius -- the scale where the attraction due to its mass is balanced by the repulsion due to dark energy. We derive generic formulae for the estimation of the maximum…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-17 Sourav Bhattacharya , Konstantinos F. Dialektopoulos , Antonio Enea Romano , Constantinos Skordis , Theodore N. Tomaras

Extracting the outcome of a quantum computation is a difficult task. In many cases, the quantum phase estimation algorithm is used to digitally encode a value in a quantum register whose amplitudes' magnitudes reflect the discrete sinc…

Quantum Physics · Physics 2022-07-04 Charlee Stefanski , Vanio Markov , Constantin Gonciulea

By confining a Bose-Einstein condensate in a vertical lattice subjected to a gravitational potential, we analyze the quantum Fisher information to determine its scaling with respect to time, system size and particle number. Our results…

Quantum Physics · Physics 2026-05-08 Hassan Manshouri , Moslem Zarei , Mehdi Abdi , Yasser Omar , Sougato Bose , Abolfazl Bayat

Starting from pure multidimensional gravity with curvature-nonlinear terms but no matter fields in the initial action, we obtain a cosmological model with two effective scalar fields related to the size of two extra factor spaces. The model…

General Relativity and Quantum Cosmology · Physics 2010-04-21 K. A. Bronnikov , S. G. Rubin , I. V. Svadkovsky

Meson mass spectra, evaluated in the framework of the relativistic model of quasi-independent quarks, are presented. Mass values are obtained with the help of numerical calculations based on the Dirac equation and by phenomenological mass…

High Energy Physics - Phenomenology · Physics 2016-12-07 V. Khruschov , V. Savrin , S. Semenov

The proper vertex amplitude is derived from the EPRL vertex by restricting to a single gravitational sector in order to achieve the correct semi-classical behaviour. We apply the proper vertex to calculate a cosmological transition…

General Relativity and Quantum Cosmology · Physics 2018-05-29 Ilya Vilensky

Quantum mode parameter estimation determines parameters governing the shape of electromagnetic modes occupied by a quantum state of radiation. Canonical examples, time delays and frequency shifts, underpin radar, lidar, and optical clocks.…

Quantum Physics · Physics 2026-03-27 Maximilian Reichert , Mikel Sanz , Nicolas Fabre

We introduce spatial deformations to an array of light sources and study how the estimation precision of the interspacing distance, d, changes with the sources of light used. The quantum Fisher information (QFI) is used as the figure of…

Quantum Physics · Physics 2017-06-28 Jasminder S. Sidhu , Pieter Kok

We show how to verify the metrological usefulness of quantum states based on the expectation values of an arbitrarily chosen set of observables. In particular, we estimate the quantum Fisher information as a figure of merit of metrological…

Quantum Physics · Physics 2017-04-25 Iagoba Apellaniz , Matthias Kleinmann , Otfried Gühne , Geza Toth

Quantum mechanics establishes the ultimate limit to the scaling of the precision on any parameter, by iden- tifying optimal probe states and measurements. While this paradigm is, at least in principle, adequate for the metrology of quantum…

We study the estimation of the reach, an ubiquitous regularity parameter in manifold estimation and geometric data analysis. Given an i.i.d. sample over an unknown $d$-dimensional $\mathcal{C}^k$-smooth submanifold of $\mathbb{R}^D$, we…

Statistics Theory · Mathematics 2022-07-14 Eddie Aamari , Clément Berenfeld , Clément Levrard
‹ Prev 1 3 4 5 6 7 10 Next ›