New general parametrization of quintessence fields and its observational constraints

Roy, Nandan; González‐Morales, Alma X.; Ureña–López, L. Arturo

doi:10.1103/physrevd.98.063530

Cited by 22 publications

(45 citation statements)

References 81 publications

(112 reference statements)

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“…While there is no evidence in favour of dynamics, there is also no evidence against dynamics of quintessence kind, as opposed to the claim disfavouring quintessence [21]. More recently, [113] have commented on the nature of the arbitrariness in the choices for quintessence potentials and claimed they are indistinguishable, since current data can constrain neither the potential param-eters nor initial conditions (what they call active and passive parameters respectively). Their study is based on parametrizing V (φ), similarly to the approach of [58].…”

Section: Model Selectionmentioning

confidence: 90%

Constraints on field flows of quintessence dark energy

et al. 2019

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The quest for understanding the late-time acceleration is haunted by an immense freedom in the analysis of dynamical models for dark energy in extended parameter spaces. Often-times having no prior knowledge at our disposal, arbitrary choices are implemented to reduce the degeneracies between parameters. We also encounter this issue in the case of quintessence fields, where a scalar degree of freedom drives the late-time acceleration. In this study, we implement a more physical prescription, the flow condition, to fine-tune the quintessence evolution for several field potentials. We find that this prescription agrees well with the most recent catalogue of data, namely supernovae type Ia, baryon acoustic oscillations, cosmic clocks and distance to last scattering surface, and it enables us to infer the initial conditions for the field, both potential and cosmological parameters. At 2σ we find stricter bounds on the potential parameters f /m pl > 0.26 and n < 0.15 for the PNGB and IPL potentials, respectively, while constraints on cosmological parameters remain extremely consistent across all assumed potentials. By implementing information criteria to assess their ability to fit the data, we do not find any evidence against thawing models, which in fact are statistically equivalent to ΛCDM, and the freezing ones are moderately disfavoured. Through our analysis we place upper bounds on the slope of quintessence potentials, consequently revealing a strong tension with the recently proposed swampland criterion, finding the 2σ upper bound of λ ∼ 0.31 for the exponential potential. * federico.tosone@roma2.infn.it †

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Section: Model Selectionmentioning

confidence: 90%

Constraints on field flows of quintessence dark energy

et al. 2019

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“…The barotropic equation of state takes the usual values of γ j = 1/3 for a relativistic species and γ j = 0 for a non-relativistic one. We define a new set of polar coordinates in the form [15][16][17][18][19][20][21][22],…”

Section: Mathematical Backgroundmentioning

confidence: 99%

“…where the α are just constant parameters. This parametrization includes a large class of quintessence potentials (see Table 1 and 2 in [15]).…”

Section: General Tracker Solutionsmentioning

confidence: 99%

“…For this, we will use the same formalism presented in Refs. [15][16][17][18], which considered a transformation of the quintessence equations of motion into a dynamical system by choosing properly defined variables in the polar form. The presence of the so-called active model parameters is clearly shown in the new equations of motion, and this is used to put constraints by means of comparison with observations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Generalized tracker quintessence models for dark energy

Ureña–López

Roy

2020

Phys. Rev. D

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We study the dynamical properties of tracker quintessence models using a general parametrisation of their corresponding potentials, and show that there is a general condition for the appearance of a tracker behavior at early times. Likewise, we determine the conditions under which the quintessence tracker models can also provide an accelerating expansion of the universe with an equation of state closer to −1. Apart from the analysis of the background dynamics, we also include linear density perturbations of the quintessence field in a consistent manner and using the same parametrisation of the potential, with which we show the influence they have on some cosmological observables. The generalized tracker models are compared to observations, and we discuss their appropriateness to ameliorate the fine-tuning of initial conditions and their consistency with the accelerated expansion of the Universe at late times.

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“…The dot denotes derivative with respect to cosmic time t , and

H = \dot{a} / a

is the Hubble parameter. By introducing the following change of variables (Cedeño et al 2017; Copeland et al 1998; Linares Cedeño et al 2020; Roy et al 2018; Ureã López 2016; Ureña López & González‐Morales 2016),

{normalΩ}_{ϕ}^{1 / 2} \sin (θ / 2) = \frac{κ \dot{ϕ}}{\sqrt{6} H}, {normalΩ}_{ϕ}^{1 / 2} \cos (θ / 2) = \frac{κ V^{1 / 2}}{\sqrt{3} H},

y_{1} \equiv - \frac{2 \sqrt{2}}{H} \partial_{ϕ} V^{1 / 2}, y_{2} \equiv - \frac{4 \sqrt{3}}{H κ} \partial_{ϕ}^{2} V^{1 / 2},

it can be shown that the Klein‐Gordon equation is written as

θ^{'} = - 3 \sin θ + y_{1},

{normalΩ}_{ϕ}^{'} = 3 (w_{italictot} - w_{ϕ}) {normalΩ}_{ϕ},

y_{1}^{'} = \frac{3}{2} (1 + w_{italictot}) y_{1} + normalΩ...

…”

Section: Background Evolutionmentioning

confidence: 99%

One‐parametric description for scalar field dark matter potentials

Cedeño

Ureña–López

2021

Astron Nachr

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We study the cosmological evolution for a scalar field dark matter model, by considering a parameterization of the evolution equations that allow us to unify in a single parameter a family of potentials: quadratic (free case), trigonometric (Axionlike case), and hyperbolic. After exploring the cosmological dynamics of this model, we perform a statistical analysis to study the viability of such model in comparison with the standard Cold Dark Matter model. We found that the free case is preferred over the other scalar field potentials, but in any case all of them are disfavored by the cosmological observations with respect to the standard model.

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New general parametrization of quintessence fields and its observational constraints

Cited by 22 publications

References 81 publications

Constraints on field flows of quintessence dark energy

Constraints on field flows of quintessence dark energy

Generalized tracker quintessence models for dark energy

One‐parametric description for scalar field dark matter potentials

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