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Related papers: Quantum induced w = -1 crossing of the quintessenc…

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We investigate the impact of quantum fluctuations on a light rolling quintessence field from three different sources, namely, from a coupling to the standard model and dark matter, from its self-couplings and from its coupling to gravity.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Mathias Garny

We present a quintessence model for the dark energy in which the quintessence scalar field is produced by the decay of a super heavy dark matter and gradually condensate to a classical scalar field. This model can explain both the smallness…

High Energy Physics - Phenomenology · Physics 2009-11-11 Houri Ziaeepour

The analysis of diffusive energy spreading in quantized chaotic driven systems, leads to a universal paradigm for the emergence of a quantum anomaly. In the classical approximation a driven chaotic system exhibits stochastic-like diffusion…

Quantum Physics · Physics 2010-07-20 Itamar Sela , James Aisenberg , Tsampikos Kottos , Doron Cohen

We study the cosmological evolutions of the equation of state for dark energy $w_{\mathrm{DE}}$ in the exponential and logarithmic as well as their combination $f(T)$ theories. We show that the crossing of the phantom divide line of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Kazuharu Bamba , Chao-Qiang Geng , Chung-Chi Lee , Ling-Wei Luo

Various physical effects resulting from decoherence are discussed in the algebraic framework. In particular, it is shown that the environment may induce not only classical properties like superselection rules, pointer states or even…

Mathematical Physics · Physics 2009-11-10 Ph. Blanchard , P. Lugiewicz , R. Olkiewicz

Recently, the observed equation of state for dark energy appears to favor values below $-1$. The tendency implies that the nature of dark energy may be quite different from that of the cosmological constant. In view of the adjustment on the…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 Yu-Ping Teng , Wolung Lee , Kin-Wang Ng

Scalar field models with non-standard kinetic terms have been proposed in the context of k-inflation, of Born-Infeld lagrangians, of phantom energy and, more in general, of low-energy string theory. In general, scalar fields are expected to…

High Energy Physics - Theory · Physics 2009-11-10 Luca Amendola

Recent data from DESI, in combination with other data, provide moderate evidence of dynamical dark energy, $w\neq-1$. In the $w_0, w_a$ parametrization of $w$, there is a preference for a phantom crossing, $w<-1$, at redshift $z\sim0.5$. In…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-27 Bikash R. Dinda , Roy Maartens

An oscillating scalar field as a quintessence model for dark energy is proposed. The case of a power-law potential is particularly intriguing and is the focus of the present article. In this model the equation of state w_{OQ} of dark energy…

Astrophysics · Physics 2007-11-26 Je-an Gu

Plasmas are usually described using classical equations. While this is often a good approximation, where are situations when a quantum description is motivated. In this paper we will include several quantum effects, ranging from particle…

Plasma Physics · Physics 2017-08-23 G. Brodin , M. Marklund

Quantum mechanics for a four-state-system is derived from classical statistics. Entanglement, interference, the difference between identical fermions or bosons and the unitary time evolution find an interpretation within a classical…

Quantum Physics · Physics 2009-10-06 C. Wetterich

Dark energy is frequently modelled as an additional dynamical scalar field component in the Universe, referred to as "quintessence", which drives the late-time acceleration. Furthermore, the quintessence field may be coupled to dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-12 Daniela Palma , Graeme N. Candlish

To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys $w=p/\rho <-1/3$. This…

High Energy Physics - Theory · Physics 2008-12-19 Max Chaves , Douglas Singleton

A global scale-invariant Dark Energy model based on Induced Gravity with the addition of a small $R^2$ contribution is examined. The scalar field (quintessence), playing the role of Dark Energy, has a quartic potential and generates…

General Relativity and Quantum Cosmology · Physics 2025-02-14 Alessandro Tronconi , Giovanni Venturi

The landscape of causal relations that can hold among a set of systems in quantum theory is richer than in classical physics. In particular, a pair of time-ordered systems can be related as cause and effect or as the effects of a common…

Quantum Physics · Physics 2017-07-20 Katja Ried , Jean-Philippe W. MacLean , Robert W. Spekkens , Kevin J. Resch

The dynamical properties of a model of dark energy in which two scalar fields are coupled by a non-canonical kinetic term are studied. We show that overall the addition of the coupling has only minor effects on the dynamics of the two-field…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Carsten van de Bruck , Joel M. Weller

It is extraordinary that a number of observations indicate that we live in a spatially flat, low matter density Universe, which is currently undergoing a period of accelerating expansion. The effort to explain this current state has focused…

Astrophysics · Physics 2010-02-18 R. R. Caldwell

While the phenomenon of the exact crossing of energy levels is a rarely occurring event, in the case of quantum resonances associated with metastable states this phenomenon is much more frequent and various scenarios can occur. When there…

Quantum Physics · Physics 2024-03-28 Andrea Sacchetti

Dark energy away from a cosmological constant $\Lambda$ -- like early universe inflation that ends -- can be understood in terms of well defined physical behaviors. These guide dark energy into thawing or freezing classes, with $w_0$--$w_a$…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-16 Eric V. Linder

We consider stochastically quantized self-interacting scalar fields as suitable models to generate dark energy in the universe. Second quantization effects lead to new and unexpected phenomena is the self interaction strength is strong. The…

Astrophysics · Physics 2009-11-10 Christian Beck