Scalar field unification of interacting viscous dark fluid from a geometrical scalar–tensor theory of gravity

Aguilar, José Edgar Madriz; Gil-Ocaranza, A.; Montes, Mariana; Zamarripa, J.

doi:10.1016/j.dark.2020.100706

Cited by 3 publications

(4 citation statements)

References 38 publications

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“…In the second case, the models that can describe the latetime accelerated expansion of the Universe are considered [33][34][35][36][37][38][39][40][41][42][43][44][45][46]. These models have revealed to be successful in reproducing the background evolution of the Universe at late time while attempting to solve the problems of CDM, unify or replace the dark components of the Universe and be compatible with the large structure formation.…”

Section: Introductionmentioning

confidence: 99%

Ricci cosmology in light of astronomical data

2021

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Recently, a new cosmological framework, dubbed Ricci cosmology, has been proposed. Such a framework has emerged from the study of relativistic dynamics of fluids out of equilibrium in a curved background and is characterised by the presence of deviations from the equilibrium pressure in the energy–momentum tensor which are due to linear terms in the Ricci scalar and the Ricci tensor. The coefficients in front of such terms are called the second order transport coefficients and they parametrise the fluid response to the pressure terms arising from the spacetime curvature. Under the preliminary assumption that the second order transport coefficients are constant, we find the simplest solution of Ricci cosmology in which the presence of pressure terms causes a departure from the perfect fluid redshift scaling for matter components filling the Universe. In order to test the viability of this solution, we make four different ansätze on the transport coefficients, giving rise to four different cases of our model. On the physical ground of the second law of thermodynamics for fluids with non-equilibrium pressure, we find some theoretical bounds (priors) on the parameters of the models. Our main concern is then the check of each of the case against the standard set of cosmological data in order to obtain the observational bounds on the second order transport coefficients. We find those bounds also realising that Ricci cosmology model is compatible with $$\Lambda $$ Λ CDM cosmology for all the ansätze.

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Section: Introductionmentioning

confidence: 99%

Ricci cosmology in light of astronomical data

2021

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“…Dynamic system theory (DST) has intellectual roots drawn from biology, physics, mathematics, meteorology, and astronomy (Cullen et al, 2022; Mandal et al, 2023; Sujith & Unni, 2021). Its contribution to studies of human development and behaviors was introduced by Shweder et al (2009), who applied it to cognitive development, and Thelen & Bates (2003) who applied the theory to motor development.…”

Section: Literature Reviewmentioning

confidence: 99%

Parenting for Success: Exploring the Link Between Parenting Styles and Adolescents’ Academic Achievement Through Their Learning Engagement

Fute,

Oubibi,

Sun

et al. 2024

Sage Open

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Adolescents’ interaction with their parents at home is pivotal for their physical and mental health, which can further influence their academic achievement at school. However, every culture has distinctive parenting elements which are distinguishable from other cultures. This study explored the influence of parenting styles on adolescents’ academic achievement through the mediation role of learning engagement in a Chinese cultural context. A questionnaire was distributed among parents and students, and 1,557 valid responses were received and analyzed using SPSS software, PROCESS macro, Microsoft Excel, and JASP. The results indicated a positive and significant effect of parenting styles on students’ academic achievement, with students’ learning engagement partially mediating such relationship. Dimension-wise, parents’ emotional acceptance positively influenced students’ academic achievement, but rejecting and overprotecting them had negative repercussions. A comparison between fathers and mothers showed a higher effect of mothers’ parenting styles compared to that of fathers. Generally, students’ behaviors result from different forces which act in and outside them, making this study a wake-up call for cherishing collective efforts from parents, teachers, and students toward improving academic performance.

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“…It follows from (28) and (29) that the dark energy sector is governed by the ρ f , p f and extra terms Thus we can introduce the quantities…”

Section: The Cosmological Field Equationsmentioning

confidence: 99%

“…This theory is also known as geometrical gauge scalar-tensor theory of gravity [13,17]. Different topics have studied in the light of these frameworks, for example interacting quintessence scenarios [17], scalar fluctuations of the metric during inflation [18], generation of the seeds of cosmic magnetic fields during inflation [25], Higgs inflation frameworks [18,26], (1 + 2)-dimensional gravity [27] and viscous cosmology [28], among others.…”

Section: Introductionmentioning

confidence: 99%

Dark energy from a geometrical gauge scalar-tensor theory of gravity

Aguilar

Montes²,

Bernal³

2023

Phys. Scr.

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In this paper we obtain some cosmological solutions that describe the present period of accelerating expansion of the universe in the framework of a geometrical gauge scalar-tensor theory of gravity. The background geometry in the model is the Weyl integrable and we found a class of power law solutions for the Weyl scalar field when an invariant metric is employed in a power law expanding universe. We obtain a deceleration and an equation of state parameters (EoS) in agreement with PLANCK 2018 observational data for some specific parameters of the model. The deceleration parameter tends asymptotically to $-1/2$ and the phantom divide line can be crossed by the EoS parameter in this model.

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Scalar field unification of interacting viscous dark fluid from a geometrical scalar–tensor theory of gravity

Cited by 3 publications

References 38 publications

Ricci cosmology in light of astronomical data

Ricci cosmology in light of astronomical data

Parenting for Success: Exploring the Link Between Parenting Styles and Adolescents’ Academic Achievement Through Their Learning Engagement

Dark energy from a geometrical gauge scalar-tensor theory of gravity

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