Article
Physics, Multidisciplinary
Gaurav N. Gadbail, Simran Arora, P. K. Sahoo
Summary: In this study, we use the viscous generalized Chaplygin gas (VGCG) model, which is a hybrid model of bulk viscosity and generalized Chaplygin gas, as an alternate dark fluid of the universe. We investigate the dynamics of the VGCG model in the non-metricity gravity framework using a functional form f(Q) = /3Qn, with /3 and n being arbitrary constants. To constrain model parameters, we utilize observational datasets such as Observational Hubble data, Baryon Acoustic Oscillations, and Type Ia supernovae data. Our results show a transition from deceleration to an acceleration phase in the evolution of the deceleration parameter q and the equation of state (EoS) parameter w, with deviations from the ΛCDM model.
Article
Physics, Mathematical
D. V. Kapse
Summary: The Kantowski-Sachs cosmological model for viscous generalized Chaplygin gas has been studied in the Brans-Dicke theory of gravitation. The solutions of field equations are determined by considering the power-law relation for the average scale factor. Several cosmological parameters are computed and their physical importance has been discussed. Additionally, the nature of statefinder and Om diagnostics in this model has been discussed, and the conclusions of the cosmological parameter are consistent with modern observational data.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2023)
Article
Physics, Mathematical
I. Brevik, A. V. Timoshkin
Summary: In this paper, we investigate a unified description of the early and the late-time universe in the presence of a viscous holographic fluid, using the holographic principle and a generalized cut-off holographic dark energy theory.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2022)
Article
Astronomy & Astrophysics
Rodrigo von Marttens, Dinorah Barbosa, Jailson Alcaniz
Summary: Einstein's equations connect the space-time geometry to the total matter content of the cosmic substratum, but not to individual contributions of the matter species. Therefore, it is difficult to differentiate cases where dark energy interacts with dark matter from a non-interacting scenario using observational data based on time or distance measurements.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Physics, Multidisciplinary
Ajay Kumar, C. P. Singh
Summary: This paper investigates the validity of the generalized second law of thermodynamics in the viscous holographic Ricci dark energy model using different entropy approaches. The analysis shows that the model approaches a stable equilibrium thermal state and is valid throughout the universe's evolution.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Physics, Particles & Fields
A. Hernandez-Almada, Miguel A. Garcia-Aspeitia, M. A. Rodriguez-Meza, V Motta
Summary: This paper discusses a hybrid model named viscous generalized Chaplygin gas (VGCG) constructed through a generalized Chaplygin gas and bulk viscosity, with its free parameters constrained by cosmological data and Joint Bayesian analysis. The results show significant differences in dynamics and comparison with the standard cosmological model. The VGCG is identified as a potential candidate to alleviate the well-known Hubble constant tension based on the Joint analysis.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
Weiqiang Yang, Supriya Pan, Eleonora Di Valentino, Celia Escamilla-Rivera, Andronikos Paliathanasis
Summary: In this study, the unified bulk viscous scenarios are constrained using observational data from the Cosmic Microwave Background and future detections of Gravitational Wave Standard Sirens. The results suggest the presence of a time-dependent bulk viscosity in the universe, which is likely to be confirmed by future measurements. Additionally, the combination of Gravitational Wave Standard Sirens data with current cosmological probes can improve the accuracy of cosmological parameter measurements.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Abdelrahman Abdullah, Amr A. El-Zant, Ali Ellithi
Summary: Unified dark matter cosmologies combine missing matter and energy in a single fluid. The standard Chaplygin gas faces difficulty in explaining large scale structure, but a nonlinear collapse model suggests that collapse is possible for larger perturbations. Additionally, a predicted nonlinear Jeans scale constrains growth and the background dynamics of clustered Chaplygin gas cosmologies appears viable.
Article
Mechanics
Young H. Lee, Jingyi Wang, Ian D. Gates
Summary: We conducted experimental study on the effects of normal stress differences in the immiscible radial viscous fingering instability in a Hele-Shaw cell. The results showed that the effects were nonmonotonic and opposing, depending on the molecular weight of the displaced fluid and the stage of the fingering evolution. Decreases in molecular weight reduced the number of fingers and widened the finger width in the early stage, while increases in molecular weight promoted tip splitting and narrowed finger width in the early stage but suppressed tip splitting in the intermediate stage.
Article
Astronomy & Astrophysics
Aroonkumar Beesham, Mfanafuthi Siyabonga Msweli
Summary: Dark energy is believed to make up the majority of matter in the universe, and its nature remains poorly understood despite efforts to explain it. This presentation examines the relationship between two potential forms of dark energy, Chaplygin gas and bulk viscosity, and finds that they are mathematically equivalent but differ in their physical interpretation.
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2022)
Article
Physics, Multidisciplinary
E. Mahichi, Alireza Amani, M. A. Ramzanpour
Summary: This paper investigates viscous cosmological dynamics in the presence of dark matter Bose-Einstein condensation by curved-FRW background. By considering an interacting model with modified Chaplygin gas, the energy density and pressure of dark energy are derived, and cosmological parameters versus redshift parameter are found by fitting with supernova data. The study shows that the universe is currently undergoing an accelerated expansion phase, and explores the stability and instability of the present model with the sound speed parameter.
CANADIAN JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Simran Kaur, C. P. Singh
Summary: This study investigates the influence of bulk viscosity on holographic dark energy with a Granda-Oliveros infra-red cut-off. It is found that the model with bulk viscosity provides an elegant description of the early and late-time evolution of the Universe. The model is constrained through various observational data, and estimations are made for the Hubble constant, deceleration parameter, and equation of state.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Diana Broboana, Ana-Maria Bratu, Istvan Magos, Claudiu Patrascu, Corneliu Balan
Summary: The dripping regime near fluid droplet breakup has been analyzed through experiments and numerical correlations. The distribution of the zeta-coefficient was found to be a relevant parameter in analyzing and quantifying the breakup process. This study has the potential to develop new techniques and more precise procedures for determining the interfacial rheology of viscous and complex fluids.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Fluids & Plasmas
Francisco J. Carrillo, Ian C. Bourg
Summary: The study investigates the transition from fluid invasion to fracturing in soft porous media under various conditions, using a newly developed multiphase Darcy-Brinkman-Biot framework. Three distinct material failure regimes were identified, controlled by nondimensional numbers quantifying the balance of viscous, capillary, and structural forces. This study effectively decouples the effects of viscous and capillary forces on fracturing mechanics.
Article
Mechanics
Rafael Granero-Belinchon, Stefano Scrobogna
Summary: The paper examines the motion of viscous water waves and introduces a new asymptotic model. Global well-posedness in Sobolev spaces is established, as well as the global well-posedness and decay of a fourth order partial differential equation modeling bidirectional water waves with viscosity moving in deep water with or without surface tension effects.
Article
Astronomy & Astrophysics
M. Malekjani, Jianbo Lu, N. Nazari-Pooya, Lixin Xu, D. Mohammad-Zadeh Jassur, M. Honari-Jafarpour
ASTROPHYSICS AND SPACE SCIENCE
(2015)
Article
Physics, Multidisciplinary
Yang Lei, Yang Wei-Qiang, Xu Li-Xin
CHINESE PHYSICS LETTERS
(2015)
Article
Physics, Multidisciplinary
Wei Li, Lixin Xu
JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS
(2015)
Article
Astronomy & Astrophysics
Lixin Xu
Article
Astronomy & Astrophysics
Lixin Xu
Article
Physics, Particles & Fields
Jianbo Lu, Danhua Geng, Lixin Xu, Yabo Wu, Molin Liu
JOURNAL OF HIGH ENERGY PHYSICS
(2015)
Article
Physics, Particles & Fields
Wei Li, Lixin Xu
EUROPEAN PHYSICAL JOURNAL C
(2014)
Article
Physics, Multidisciplinary
Lixin Xu
INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS
(2014)
Article
Astronomy & Astrophysics
Weiqiang Yang, Lixin Xu, Yuting Wang, Yabo Wu
Article
Astronomy & Astrophysics
Suresh Kumar, Lixin Xu
Article
Physics, Multidisciplinary
Lu JianBo, Chen LiDong, Xu LiXin, Li TianQiang
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2014)
Article
Astronomy & Astrophysics
Yuhao Mu, En-Kun Li, Lixin Xu
Summary: In this paper, the reconstructed growth index is updated using a combination of Pantheon+ SNe Ia samples, observed Hubble data points, and redshift space distortion measurements. The results suggest a mild time varying growth index at low redshifts within the available data points. No significant deviation from the ΛCDM cosmology in GR was found within the 3 sigma regions, while the growth indices for f(R) and Dvali-Gabadadze-Porrati gravity are at the boundaries of the 3 sigma regions.
CLASSICAL AND QUANTUM GRAVITY
(2023)
Article
Astronomy & Astrophysics
Gang Liu, Zhihuan Zhou, Yuhao Mu, Lixin Xu
Summary: In this paper, the interaction between early dark energy and scalar field dark matter is investigated. A coupled model is proposed to address the tension in Hubble constant and S8 parameter. It is found that while the model alleviates the tension in Hubble constant, it exacerbates the tension in S8 parameter. The introduction of interaction between early dark energy and dark matter is suggested to mitigate the negative impact.
Article
Astronomy & Astrophysics
Hsien-Hao Mei, Wei-Tou Ni, Wei-Ping Pan, Lixin Xu, Sperello di Serego Alighieri
ASTROPHYSICAL JOURNAL
(2015)
