English
Related papers

Related papers: Using machine learning to optimise chameleon fifth…

200 papers

This paper proposes a novel paradigm for machine learning that moves beyond traditional parameter optimization. Unlike conventional approaches that search for optimal parameters within a fixed geometric space, our core idea is to treat the…

Machine Learning · Computer Science 2025-10-31 Di Zhang

We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential…

General Relativity and Quantum Cosmology · Physics 2017-12-12 Y. Bisabr , F. Ahmadi

A common view in evolutionary biology is that mutation rates are minimised. However, studies in combinatorial optimisation and search have shown a clear advantage of using variable mutation rates as a control parameter to optimise the…

Populations and Evolution · Quantitative Biology 2019-08-27 Roman V. Belavkin , Alastair Channon , Elizabeth Aston , John Aston , Rok Krasovec , Christopher G. Knight

Training model to generate data has increasingly attracted research attention and become important in modern world applications. We propose in this paper a new geometry-based optimization approach to address this problem. Orthogonal to…

Machine Learning · Computer Science 2017-08-18 Trung Le , Hung Vu , Tu Dinh Nguyen , Dinh Phung

We derive analytic solutions of a chameleon scalar field $\phi$ that couples to a non-relativistic matter in the weak gravitational background of a spherically symmetric body, paying particular attention to a field mass $m_A$ inside of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Takashi Tamaki , Shinji Tsujikawa

The chameleon mechanism appearing in massive tensor-scalar theory of gravity can effectively reduce the nonminimal coupling between the scalar field and matter. This mechanism is invoked to reconcile cosmological data requiring introduction…

General Relativity and Quantum Cosmology · Physics 2017-02-22 A. Hees , A. Füzfa

Theories of gravity that incorporate new scalar degrees of freedom typically require screening mechanisms to ensure consistency with Solar System tests. One widely-studied mechanism -- the chameleon -- can lead to violations of the…

Astrophysics of Galaxies · Physics 2020-11-24 A. P. Naik , N. W. Evans , E. Puchwein , H. Zhao , A. -C. Davis

This work provides the first comparison of the symmetron and dilaton fields in white dwarfs. We show how these screening mechanisms behave inside {such stars} and their impact on stellar properties. Employing a custom-developed shooting…

General Relativity and Quantum Cosmology · Physics 2025-05-15 Joan Bachs-Esteban , Ilídio Lopes , Javier Rubio

Nonlinear scalar-tensor theories of gravity have been considered as candidates for dark matter and dark energy. Often, they possess screening mechanisms, which allow the fifth force mediated by the additional scalar degree(s) of freedom to…

High Energy Physics - Theory · Physics 2026-04-08 Peter Millington , Michael Udemba

We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Ph. Brax , R. Rosenfeld , D. A. Steer

Empirical force fields employed in molecular dynamics simulations of complex systems can be optimised to reproduce experimentally determined structural and thermodynamic properties. In contrast, experimental knowledge about the rates of…

Statistical Mechanics · Physics 2022-07-12 P. G. Bolhuis , Z. F. Brotzakis , B. G. Keller

Chameleon mechanism appearing in massive tensor-scalar theory of gravity can effectively reduce locally the non-minimal coupling between the scalar field and matter. This mechanism is invoked to reconcile large-scale departures from general…

General Relativity and Quantum Cosmology · Physics 2015-03-19 A. Hees , A. Füzfa

We study constraints on f(R) dark energy models from solar system experiments combined with experiments on the violation of equivalence principle. When the mass of an equivalent scalar field degree of freedom is heavy in a region with high…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Salvatore Capozziello , Shinji Tsujikawa

The Constrained Minimal Supersymmetric Standard Model (CMSSM) is one of the simplest and most widely-studied supersymmetric extensions to the standard model of particle physics. Nevertheless, current data do not sufficiently constrain the…

High Energy Physics - Phenomenology · Physics 2015-03-13 Yashar Akrami , Pat Scott , Joakim Edsjö , Jan Conrad , Lars Bergström

In many situations, simulation models are developed to handle complex real-world business optimisation problems. For example, a discrete-event simulation model is used to simulate the trailer management process in a big Fast-Moving Consumer…

Neural and Evolutionary Computing · Computer Science 2019-07-18 Dylan Rijnen , Jason Rhuggenaath , Paulo R. de O. da Costa , Yingqian Zhang

Spatial optimization is often overlooked in many computer vision tasks. Filters should be able to recognize the features of an object regardless of where it is in the image. Similarity search is a crucial task where spatial features decide…

Computer Vision and Pattern Recognition · Computer Science 2024-04-11 Md. Farhadul Islam , Md. Tanzim Reza , Meem Arafat Manab , Mohammad Rakibul Hasan Mahin , Sarah Zabeen , Jannatun Noor

In N-body simulations of collisionless stellar systems, the forces are softened to reduce the shot noise. Softening modifies gravity at r=|x-y| smaller than softening length epsilon and the softened forces are increasingly biased for ever…

Astrophysics · Physics 2009-10-31 Walter Dehnen

In evolutionary robotics, robot morphologies are designed automatically using evolutionary algorithms. This creates a body-brain optimization problem, where both morphology and control must be optimized together. A common approach is to…

Robotics · Computer Science 2026-01-08 K. Ege de Bruin , Kyrre Glette , Kai Olav Ellefsen

The training of molecular models of quantum mechanical properties based on statistical machine learning requires large datasets which exemplify the map from chemical structure to molecular property. Intelligent a priori selection of…

Experiments on the violation of equivalence principle (EP) and solar system give a number of constraints in which any modified gravity model must satisfy them. We study these constraints on a kind of $f(R)$ gravity as $f(R) = R(1\pm…

General Relativity and Quantum Cosmology · Physics 2014-01-20 Kh. Saaidi , A. Aghamohammadi