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Here we consider a scenario in which dark energy is associated with the apparent area of a surface in the early universe. In order to resemble the cosmological constant at late times, this hypothetical reference scale should maintain an…

Astrophysics · Physics 2010-10-27 Fergus Simpson

We define a Causal Decision Problem as a Decision Problem where the available actions, the family of uncertain events and the set of outcomes are related through the variables of a Causal Graphical Model $\mathcal{G}$. A solution criteria…

Artificial Intelligence · Computer Science 2019-02-07 M. Gonzalez-Soto , L. E. Sucar , H. J. Escalante

Deep Learning models have shown success in a large variety of tasks by extracting correlation patterns from high-dimensional data but still struggle when generalizing out of their initial distribution. As causal engines aim to learn…

Machine Learning · Computer Science 2024-01-02 Gaël Gendron , Michael Witbrock , Gillian Dobbie

Are Dark Matter the result of uncalculated addition derivatives? The need to introduce dark matter dark becomes unnecessary if we consider that, the phenomenon of dark matter is a result of not computing the additional derivatives of the…

General Physics · Physics 2025-01-08 T. F. Kamalov , O. A. Volkova , Hassan M. H. Khamis , N. V. Evdokimov , Yu. T. Kamalov

We test a particular theory of dark matter in which dark matter axions form ring "caustics" in the plane of the Milky Way against actual observations of Milky Way stars. According to this theory, cold, collisionless dark matter particles…

Astrophysics of Galaxies · Physics 2015-09-23 Julie Dumas , Heidi J. Newberg , Bethany Niedzielski , Adam Susser , Jeffery M. Thompson , Jake Weiss , Kim M. Lewis

The main task of this paper is to realize a cosmic observational compatible universe in the framework of holographic dark energy model when the Hubble horizon $H$ is taken as the role of an IR cut-off. When the model parameter $c$ of a time…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-28 Lixin Xu

This dissertation investigates thermodynamic, emergent and holographic aspects of gravity in the context of causal diamonds. We obtain a gravitational first law for causal diamonds in maximally symmetric spacetimes and argue that these…

High Energy Physics - Theory · Physics 2019-08-16 Manus R. Visser

Current cosmological data indicate that our universe contains a substantial component of dark vacuum energy that is driving the cosmos to accelerate. We examine the immediate and longer term consequences of this dark energy (assumed here to…

Astrophysics · Physics 2010-12-09 Michael T. Busha , Fred C. Adams , Risa H. Wechsler , August E. Evrard

A cosmological model of an holographic dark energy interacting with dark matter throughout a decaying term of the form $Q=3(\lambda_1\rho_{DE} + \lambda_2\rho_m) H$ is investigated. General constraint on the parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Norman Cruz , Samuel Lepe , Francisco Pena , Joel Saavedra

Recent observations show that our universe is accelerating by dark energy, so it is important to investigate the thermodynamical properties of it. The Undulant Universe is a model with equation of state $\omega(a)=-\cos(b\ln a)$ for dark…

Astrophysics · Physics 2010-06-18 Tian Lan , Tong-Jie Zhang , Bao-Quan Wang

We study the evolution of the universe by assuming an integrated model, which involves interacting dark energy and holographic principle with Hubble scale as IR cutoff. First we determined the interaction rate at which matter is converting…

General Relativity and Quantum Cosmology · Physics 2020-10-14 Bibekananda Nayak

We use a WKB approximation to establish a relation between the wavefront velocity in a strongly coupled theory and the local speed of light in a holographic dual, with our main focus put on systems with Lifshitz scaling with dynamical…

High Energy Physics - Theory · Physics 2010-12-09 Carlos Hoyos , Peter Koroteev

A novel topological and computational method for 'motion' is described. Motion is constrained by inequalities in terms of Kolmogorov Complexity. Causality is obtained as the output of a high-pass filter, passing through only high values of…

Computational Complexity · Computer Science 2012-04-26 Dara O. Shayda

Employing the modified entropy-area relation suggested by Tsallis and Cirto \cite{non3}, and the holographic hypothesis, a new holographic dark energy (HDE) model is proposed. Considering a flat Friedmann-Robertson-Walker (FRW) universe in…

General Relativity and Quantum Cosmology · Physics 2018-04-19 M. Tavayef , A. Sheykhi , Kazuharu Bamba , H. Moradpour

In this Essay we address several fundamental issues in cosmology: What is the nature of dark energy and dark matter? Why is the dark sector so different from ordinary matter? Why is the effective cosmological constant non-zero but so…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Y. Jack Ng

The reason for the present accelerated expansion of the Universe stands as one of the most profound questions in the realm of science, with deep connections to both cosmology and fundamental physics. From a cosmological point of view,…

General Relativity and Quantum Cosmology · Physics 2024-08-22 Peixiang Ji , Lijing Shao

A systematic search for different viable models of the dark energy universe, all of which give rise to finite-time, future singularities, is undertaken, with the purpose to try to find a solution to this common problem. After some work, a…

High Energy Physics - Theory · Physics 2015-05-27 A. J. López-Revelles , E. Elizalde

It is currently unknown whether the laws of physics permit time travel into the past. While general relativity indicates the theoretical possibility of causality violation, it is now widely accepted that a theory of quantum gravity must…

Quantum Physics · Physics 2014-01-03 Jacques Pienaar

Interactions between internet users are mediated by their devices and the common support infrastructure in data centres. Keeping track of causality amongst actions that take place in this distributed system is key to provide a seamless…

Distributed, Parallel, and Cluster Computing · Computer Science 2016-08-12 Seyed Hossein Haeri , Peter Van Roy , Carlos Baquero , Christopher Meiklejohn

Since the discovery of the accelerated expansion of the Universe, the constraints on the equation of state $w_\text{DE}$ of dark energy, the stress-energy component responsible for the acceleration, have tightened significantly. These…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-09 Fabian Schmidt