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The standard cosmological model, LCDM, provides an excellent fit to Cosmic Microwave Background (CMB) data. However, the model has well known problems. For example, the cosmological constant, is fine-tuned to 1 part in 10^100 and the cold…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 T. Shanks , R. W. F. Johnson , J. A. Schewtschenko , J. R. Whitbourn

We present a new blind formulation of the Cosmic Microwave Background (CMB) inference problem. The approach relies on a phenomenological model of the multi-frequency microwave sky without the need for physical models of the individual…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-30 Flavien Vansyngel , Benjamin D. Wandelt , Jean-François Cardoso , Karim Benabed

The Cosmic Defect theory has been confronted with four observational constraints: primordial nuclear species abundances emerging from the big bang nucleosynthesis; large scale structure formation in the universe; cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 N. Radicella , M. Sereno , A. Tartaglia

By assuming a phenomenological form for the ratio of the DE and DM densities $\rho_X\propto \rho_{m} a^{\xi}$ (Dalal et al.2001), we discuss the cosmic coincidence problem in light of current observational data. $\xi$ is a key parameter to…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-11 Yun Chen , Zong-Hong Zhu , J. S. Alcaniz , Yungui Gong

The standard paradigm of cosmology assumes two distinct dark components, namely dark matter and dark energy. However, the necessity of splitting the dark-side world into two sectors has not been experimentally or theoretically proven.…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-12 Yan Su , Zhiqi Huang , Yanhong Yao , Junchao Wang , Jianqi Liu

One of the main goals of physical cosmology is to reconstruct the expansion history of the universe and finding the actual model of dark energy. In this article I review the difficulties of understanding dark energy and discuss about two…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-30 Arman Shafieloo

Observation of thousands of type Ia supernovae should offer the most direct approach to probe the dark energy content of the universe. This will be undertaken by future large ground-based surveys followed by a space mission (SNAP/JDEM). We…

Astrophysics · Physics 2009-11-10 J. -M. Virey , P. Taxil , A. Tilquin , A. Ealet , D. Fouchez , C. Tao

Machine learning models are vulnerable to adversarial examples: minor perturbations to input samples intended to deliberately cause misclassification. While an obvious security threat, adversarial examples yield as well insights about the…

Cryptography and Security · Computer Science 2019-11-19 Kathrin Grosse , David Pfaff , Michael Thomas Smith , Michael Backes

We perform a Bayesian model selection analysis for different classes of phenomenological coupled scenarios of dark matter and dark energy with linear and non-linear interacting terms. We use a combination of some of the latest cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-08 Antonella Cid , Beethoven Santos , Cassio Pigozzo , Tassia Ferreira , Jailson Alcaniz

The high-quality cosmological data, which became available in the last decade, have thrusted upon us a rather preposterous composition for the universe which poses one of the greatest challenges theoretical physics has ever faced: the…

Astrophysics · Physics 2015-06-24 J. S. Alcaniz

From a systems biology perspective the majority of cancer models, although interesting and providing a qualitative explanation of some problems, have a major disadvantage in that they usually miss a genuine connection with experimental…

Statistics Theory · Mathematics 2023-05-25 Zuzanna Szymańska , Jakub Skrzeczkowski , Błażej Miasojedow , Piotr Gwiazda

We use all available baryon acoustic oscillation distance measurements and Hubble parameter data to constrain the cosmological constant $\Lambda$, dynamical dark energy, and spatial curvature in simple cosmological models. We find that the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-19 Joseph Ryan , Sanket Doshi , Bharat Ratra

Everpresent $\Lambda$ is a cosmological scenario in which the observed cosmological "constant" $\Lambda$ fluctuates between positive and negative values with a vanishing mean, and with a magnitude comparable to the critical density at any…

General Relativity and Quantum Cosmology · Physics 2018-10-17 Nosiphiwo Zwane , Niayesh Afshordi , Rafael D. Sorkin

We carry out an independent re-analysis of the Dark Energy Spectroscopic Instrument (DESI) public dataset, focusing on extensions to the standard cosmological model, $\Lambda$CDM. Utilizing the dataset and Effective Field Theory (EFT)-based…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-15 Anton Chudaykin , Mikhail M. Ivanov , Oliver H. E. Philcox

Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda; nowadays the concept is termed dark energy or quintessence. Physics also suggests the dark energy…

Astrophysics · Physics 2008-11-26 P. J. E. Peebles , Bharat Ratra

Due to their intuitive appeal, Bayesian methods of modeling and uncertainty quantification have become popular in modern machine and deep learning. When providing a prior distribution over the parameter space, it is straightforward to…

Machine Learning · Statistics 2025-06-05 Ivan Melev , Goeran Kauermann

We explore Bayesian reasoning as a means to quantify uncertainty in neural networks for question answering. Starting with a multilayer perceptron on the Iris dataset, we show how posterior inference conveys confidence in predictions. We…

Computation and Language · Computer Science 2025-12-22 Riccardo Di Sipio

Cosmology is operating now on a well established and tightly constraining empirical basis. The relativistic LambdaCDM hot big bang theory is consistent with all the present tests; it has become the benchmark. But the many open issues in…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 P. J. E. Peebles

The recent astronomical measurements of distant supernovae as well as other observations indicate that our universe is presently accelerating. There are different proposals for the explanation of this acceleration, such as the cosmological…

Astrophysics · Physics 2008-11-26 Marek Szydlowski , Wlodzimierz Godlowski

We have reanalysed constraints on the equation of state parameter, w_Q = P/rho, of the dark energy, using several cosmological data sets and relaxing the usual constraint w_Q > -1. We find that combining Cosmic Microwave Background, large…

Astrophysics · Physics 2009-11-07 Steen Hannestad , Edvard Mortsell
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