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Related papers: Quintessence or Phoenix?

200 papers

We review the findings for the values of the cosmological parameters as derived from high-redshift SNIa measurements. The most recent results confirm the picture of a non-empty inflationary Universe that is consistent with a cosmological…

Astrophysics · Physics 2009-11-10 Nino Panagia

Recent observations suggest that the accelerated expansion of the Universe at late times is caused by a temporally changing dark energy component, rather than the constant one in the standard $\Lambda$CDM scenario. In this context…

General Relativity and Quantum Cosmology · Physics 2025-11-05 Artur Alho , Elsa Bernholm , Claes Uggla

We study the interesting problem of whether it is possible to distinguish composite from elementary particles. In particular we generalize a model-independent approach of S. Weinberg to the case of unstable particles. This allows us to…

High Energy Physics - Phenomenology · Physics 2008-11-26 V. Baru , J. Haidenbauer , C. Hanhart , Yu. Kalashnikova , A. Kudryavtsev

We consider a question in what condition a mixed state which can be decomposed in different ways cannot be described by a single set of hidden variables. The condition is closely related with Bell theorem.

Quantum Physics · Physics 2025-05-27 Won-Young Hwang

Parameter inference is essential when interpreting observational data using mathematical models. Standard inference methods for differential equation models typically rely on obtaining repeated numerical solutions of the differential…

Methodology · Statistics 2024-12-16 Alexander Johnston , Ruth E. Baker , Matthew J. Simpson

Hypothesis testing and model choice are quintessential questions for statistical inference and while the Bayesian paradigm seems ideally suited for answering these questions, it faces difficulties of its own ranging from prior modelling to…

Methodology · Statistics 2022-06-15 Christian P Robert

Quintessence -- the energy density of a slowly evolving scalar field -- may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea in the light of the cosmological constant problem. Cosmological…

Astrophysics · Physics 2009-11-07 Michael Doran , Christof Wetterich

One of the most important questions nowadays in physics concerns the nature of the so-called dark energy. It is also a consensus among cosmologists that such a question will not be answered on the basis only of observational data. However,…

Astrophysics · Physics 2008-11-26 Deepak Jain , J. S. Alcaniz , Abha Dev

Defining the observable ${\bf \phi}$ canonically conjugate to the number observable ${\bf N}$ has long been an open problem in quantum theory. The problem stems from the fact that ${\bf N}$ is bounded from below. In a previous work we have…

Quantum Physics · Physics 2007-05-23 Gilad Gour

For decades, H_0 and q_0 were the quest of cosmology, as they promised to characterize our "world model" without reference to a specific cosmological framework. Using Monte Carlo simulations, we show that q_0 cannot be directly measured…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Abraham R. Neben , Michael S. Turner

Epistemological consequences of quantum nonlocality (entanglement) are discussed under the assumption of a universally valid Schr\"odinger equation in the absence of hidden variables. This leads inevitably to a {\it many-minds…

Quantum Physics · Physics 2007-05-23 H. D. Zeh

Recently we proposed a new approach to the testing of dark energy models based on the observational data. In that work we focused particularly on quintessence models for demonstration and invoked a widely used parametrization of the dark…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-22 Chien-Wen Chen , Je-An Gu , Pisin Chen

The model-independent piecewise parametrizations (0-spline, linear-spline and cubic-spline) are used to estimate constraints of equation of state of dark energy ($w_{de}$) from current observational data (including SNIa, BAO and Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-11 Qiping Su , Xi He , Rong-Gen Cai

We point out an important hidden inconsistency in Fermi's probability of the quantum states that engendered inconsistent/inaccurate equations-of-state extensively used in the literature to model nonideal plasma systems. The importance of…

Plasma Physics · Physics 2015-05-30 Mofreh R. Zaghloul

We address some recent erroneous claim that $H_0$ observations are difficult to accommodate with LTB cosmological models, showing how to construct solutions in agreement with an arbitrary value of $H_0$ by re-writing the exact solution in…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-11 Antonio Enea Romano

We examine a dark energy model where a scalar unparticle degree of freedom plays the role of quintessence. In particular, we study a model where the unparticle degree of freedom has a standard kinetic term and a simple mass potential, the…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 De-Chang Dai , Sourish Dutta , Dejan Stojkovic

The analysis of scientific data and complex multivariate systems requires information quantities that capture relationships among multiple random variables. Recently, new information-theoretic measures have been developed to overcome the…

Machine Learning · Computer Science 2024-06-10 Mustapha Bounoua , Giulio Franzese , Pietro Michiardi

It is often incorrectly assumed that the number of microstates \Omega (E,V,N,...) available to an isolated system can have arbitrary dependence on the extensive variables E,V,N, .... However, this is not the case for natural systems which…

Statistical Mechanics · Physics 2013-07-31 K. Michaelian , I. Santamaría-Holek , A. Pérez-Madrid

Recently, it has been argued that no extension of quantum theory can have improved predictive power under a strong assumption of free choice of the experimental settings and validity of quantum mechanics. Here, under a different free choice…

Quantum Physics · Physics 2013-04-29 GianCarlo Ghirardi , Raffaele Romano

This chapter acknowledges a gap between the ``non-individuals'' interpretation of quantum mechanics and our world of experience, and begins to bridge it. Section 1 states the problem with Abner Shimony's ``Phenomenological principle'';…

History and Philosophy of Physics · Physics 2025-05-22 Raoni Arroyo