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We describe and analyze algorithms for shape-constrained symbolic regression, which allows the inclusion of prior knowledge about the shape of the regression function. This is relevant in many areas of engineering -- in particular whenever…

Neural and Evolutionary Computing · Computer Science 2021-07-21 Christian Haider , Fabricio Olivetti de França , Bogdan Burlacu , Gabriel Kronberger

Morse projections are well-known in chemistry and allow one, within a Morse potential approximation, to redefine the potential in a simple quadratic form. The latter, being a non-linear transform, is also very helpful for machine learning…

Chemical Physics · Physics 2023-01-06 Fabio E. A. Albertani , Alex J. W. Thom

Cross-correlating two different types of galaxy gives rise to parity breaking in the correlation function that derives from differences in the galaxies' properties and environments. This is typically associated with a difference in galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 Darsh Kodwani , Harry Desmond

The main aim of this paper is to analyse minimally-coupled scalar-fields -- quintessence and phantom -- as the main candidates to explain the accelerated expansion of the universe and compare its observables to current cosmological…

General Relativity and Quantum Cosmology · Physics 2021-02-10 J. Alberto Vázquez , David Tamayo , Anjan A. Sen , Israel Quiros

Scalar field theories that possess a Vainshtein mechanism are able to dynamically suppress the associated fifth forces in the presence of massive sources through derivative non-linearities. The resulting equations of motion for the scalar…

General Relativity and Quantum Cosmology · Physics 2015-08-18 Jolyon K. Bloomfield , Clare Burrage , Anne-Christine Davis

We consider $f(R)$ modified gravity theory incorporating the chameleon mechanism to address galactic dynamics. By employing the metric formalism and utilizing a conformal transformation, we simplify the field equations and describe the…

General Relativity and Quantum Cosmology · Physics 2024-09-04 Gayatri Mohan , Umananda Dev Goswami

We model the chameleon effect on cosmological statistics for the modified gravity f(R) model of cosmic acceleration. The chameleon effect, required to make the model compatible with local tests of gravity, reduces force enhancement as a…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-07 Yin Li , Wayne Hu

The problem of automatic software generation is known as Machine Programming. In this work, we propose a framework based on genetic algorithms to solve this problem. Although genetic algorithms have been used successfully for many problems,…

Neural and Evolutionary Computing · Computer Science 2023-04-04 Shantanu Mandal , Todd A. Anderson , Javier S. Turek , Justin Gottschlich , Shengtian Zhou , Abdullah Muzahid

Modified theories of gravity have received a renewed interest due to their ability to account for the cosmic acceleration. In order to satisfy the solar system tests of gravity, these theories need to include a screening mechanism that…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-15 Jeremy Sakstein , Bhuvnesh Jain , Vinu Vikram

Within the landscape of modified theories of gravity, progress in understanding the behaviour of, and developing tests for, screening mechanisms has been hindered by the complexity of the field equations involved, which are nonlinear in…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Jonathan Braden , Clare Burrage , Benjamin Elder , Daniela Saadeh

The chameleon scalar field is considered as a possible cause of accelerated expansion of the Universe. The chameleon field induces an interaction potential between a particle and a massive body. Previous experiments with falling cold…

Nuclear Experiment · Physics 2015-06-18 Yu. N. Pokotilovski

Aims. We investigate the gravitational redshift in clusters of galaxies in the symmetron and Hu-Sawicky $f(R)$ models. The characteristic feature of both models is the screening mechanism that hides the fifth force in dense environments…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Max B. Gronke , Claudio Llinares , David F. Mota

Chameleon and similar (symmetron and dilation) theories of gravity can exhibit new and interesting features on cosmological scales whilst screening the modifications on small scales thereby satisfying solar system tests of general…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-17 Jeremy Sakstein

This paper introduces Force Matching (ForM), a novel framework for generative modeling that represents an initial exploration into leveraging special relativistic mechanics to enhance the stability of the sampling process. By incorporating…

Machine Learning · Computer Science 2025-02-13 Yang Cao , Bo Chen , Xiaoyu Li , Yingyu Liang , Zhizhou Sha , Zhenmei Shi , Zhao Song , Mingda Wan

We propose a novel method for refining force-field parameters of protein systems. In this method, the agreement of the secondary-structure stability and instability between the protein conformations obtained by experiments and those…

Biological Physics · Physics 2013-01-08 Yoshitake Sakae , Yuko Okamoto

Genetic algorithms are a powerful tool in optimization for single and multi-modal functions. This paper provides an overview of their fundamentals with some analytical examples. In addition, we explore how they can be used as a parameter…

The chameleon screening mechanism has been constrained many a time using dynamic and kinematic galaxy cluster observables. Current constraints are, however, insensitive to different mass components within galaxy clusters and have been…

In simulations of crystals, unlike liquids or gases, it may happen that the properties of the studied system depend not only on the volume of the simulation cell but also on its shape. For such cases it is desirable to change the shape of…

Computational Physics · Physics 2022-10-04 A. Baumketner

We describe and demonstrate the potential of a new and very efficient method for simulating certain classes of modified gravity theories, such as the widely studied $f(R)$ gravity models. High resolution simulations for such models are…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-14 Sownak Bose , Baojiu Li , Alexandre Barreira , Jian-hua He , Wojciech A. Hellwing , Kazuya Koyama , Claudio Llinares , Gong-Bo Zhao

Cosmological simulations of structure formation follow the collisionless evolution of dark matter starting from a nearly homogeneous field at early times down to the highly clustered configuration at redshift zero. The density field is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Francesca Iannuzzi , Klaus Dolag
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