Generalized dark energy interactions with multiple fluids

Bruck, Carsten van de; Mifsud, Jurgen; Mimoso, José P.; Nunes, Nelson J.

doi:10.1088/1475-7516/2016/11/031

Cited by 35 publications

(62 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…IV we follow to rewrite the equations as a dynamical system in terms of dimensionless variables with physical interest and proceed to the study of the single-fluid scenario for both pressureless and relativist fluids. Additionally we comment on the novelties associated with the introduction of the kinetic dependence, in contrast with [77] and also comment on some of the "pathologies" and features found in previous works. In Sec.…”

mentioning

confidence: 83%

“…• If µ = 0 the system reduces to disformally coupled quintessence, in the case where the conformal and disformal functions depend only on the field itself. This was studied in [59,77].…”

Section: Dynamical Systemmentioning

confidence: 99%

“…This means that, in order to draw the full space, we first need to compactify it.To do so, we introduce the variable (following the procedure in [77])…”

Section: A Phase Space and Invariant Setsmentioning

confidence: 99%

See 2 more Smart Citations

Disformally coupled quintessence

Teixeira

Nunes

2020

Phys. Rev. D

Self Cite

View full text Add to dashboard Cite

In this work we consider a cosmological model in which dark energy is portrayed by a canonical scalar field which is allowed to couple to the other species by means of a disformal transformation of the metric. We revisit the current literature by assuming that the disformal function in the metric transformation can depend both on the scalar field itself and on its derivatives, encapsulating a wide variety of scalar-tensor theories. This generalisation also leads to new and richer phenomenology, explaining some of the features found in previously studied models. We present the background equations and perform a detailed dynamical analysis, from where new disformal fixed points emerge, that translate into novel cosmological features. These include early scaling regimes between the coupled species and broader stability parameter regions. However, viable cosmological models seem to have suppressed disformal late-time contributions. I. IntroductionSince 1998 that we have been witnessing growing observational confirmation of the present accelerated expansion of the Universe [1][2][3][4]. This phenomenon can be attributed to an exotic fluid, the so-called Dark Energy (DE), which must amount to about 70% of the total content of the Universe, and whose effective negative pressure can successfully explain the observations (see [5][6][7] for recent reviews). Presently, the ΛCDM model is the most well-accepted cosmological model, consisting of a cosmological constant dark energy source, Λ, plus a dark matter component, needed in order to make formation of structure possible in the Universe [8]. However, this paradigm faces some theoretical inconsistencies [9], motivating extensions of the concept of dark energy to a scalar field, with General Relativity as the underlying gravitational theory [10][11][12]. These scalar field based models, albeit simple, can give rise to very complex and rich phenomenologies, while making predictions that are testable according to observational constraints [4]. In the plainest scenarios, DE is portrayed as a canonical scalar field, the quintessence field, which does not interact with the other components in the Universe [13,14]. However, there is no fundamental reason to assume such a constraint and, in the simplest extension, the scalar field is allowed to couple non-minimally to the matter sector [15][16][17][18][19][20][21][22][23].One straightforward procedure for introducing a non-trivial coupling between the scalar field and matter is to consider that matter particles propagate in geodesics of a transformed metric,ḡ µν , related to the gravitational metric, g µν , by means of a field-dependent transformation. When this transformation corresponds to a rescaling of the metric we speak of conformal transformations, which affect the length of time-like and space-like intervals and the norm of time-like and space-like vectors while leaving the light cones unchanged:where C is the conformal factor. Conformal transformations are known to preserve the structure of Scalar-Tensor theories of the B...

show abstract

mentioning

confidence: 83%

“…• If µ = 0 the system reduces to disformally coupled quintessence, in the case where the conformal and disformal functions depend only on the field itself. This was studied in [59,77].…”

Section: Dynamical Systemmentioning

confidence: 99%

See 1 more Smart Citation

Disformally coupled quintessence

Teixeira

Nunes

2020

Phys. Rev. D

Self Cite

View full text Add to dashboard Cite

show abstract

“…Essentially these interacting models invoke energy exchange between the dark components and a small degree of momentum exchange. These scenarios have been intensively investigated in the literature for several dark sector coupling functions and observational approximations [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. It has recently been shown that the current observational data can favor the late time interaction between DE and DM [27][28][29][30][31][32][33][34].…”

Section: Introductionmentioning

confidence: 99%

Observational constraints on dark matter–dark energy scattering cross section

Kumar

Nunes

2017

Eur. Phys. J. C

View full text Add to dashboard Cite

In this letter, we report precise and robust observational constraints on the dark matter-dark energy scattering cross section, using the latest data from cosmic microwave background (CMB) Planck temperature and polarization, baryon acoustic oscillations (BAO) measurements and weak gravitational lensing data from CanadaFrance-Hawaii Telescope Lensing Survey (CFHTLenS). The scattering scenario consists of a pure momentum exchange between the dark components, and we find σ d < 10 −29 cm 2 (m dm c 2 /Gev) at 95% CL from the joint analysis (CMB + BAO + CFHTLenS), where m dm is a typical dark matter particle mass. We notice that the scattering among the dark components may influence the growth of large scale structure in the Universe, leaving the background cosmology unaltered.

show abstract

“…However, in order to transform general scalar-tensor theories to Einstein frame, we need transformations that are more general than the conformal transformation. It has been shown that subclasses of the GLPV theory which is the generalization of the Horndeski theory can be transformed to the Einstein frame using the disformal transformation defined as [19][20][21] g μν = C(φ)g μν + D(φ, X )φ ,μ φ ,ν ,…”

Section: Introductionmentioning

confidence: 99%

Dynamics of the universe with disformal coupling between the dark sectors

Karwan

Sapa

2017

Eur. Phys. J. C

View full text Add to dashboard Cite

We use a dynamical analysis to study the evolution of the universe at late time for the model in which the interaction between dark energy and dark matter is inspired by a disformal transformation. We extend the analysis in the existing literature by assuming that the disformal coefficient depends both on the scalar field and its kinetic terms. We find that the dependence of the disformal coefficient on the kinetic term of scalar field leads to two classes of the scaling fixed points that can describe the acceleration of the universe at late time. The first class exists only for the case where the disformal coefficient depends on the kinetic terms. The fixed points in this class are saddle points unless the slope of the conformal coefficient is sufficiently large. The second class can be viewed as the generalization of the fixed points studied in the literature. According to the stability analysis of these fixed points, we find that the stable fixed point can take two different physically relevant values for the same value of the parameters of the model. These different values of the fixed points can be reached for different initial conditions for the equation of state parameter of dark energy. We also discuss the situations in which this feature disappears.

show abstract

Generalized dark energy interactions with multiple fluids

Cited by 35 publications

References 55 publications

Disformally coupled quintessence

Disformally coupled quintessence

Observational constraints on dark matter–dark energy scattering cross section

Dynamics of the universe with disformal coupling between the dark sectors

Contact Info

Product

Resources

About