Cosmic acceleration with bulk viscosity in an anisotropic f(R, Lm) background  

在线阅读下载全文

作  者:Raja Solanki Bina Patel Lakhan V Jaybhaye P K Sahoo 

机构地区:[1]Department of Mathematics,Birla Institute of Technology and Science-Pilani,Hyderabad Campus,Hyderabad-500078,India [2]Department of Mathematical Sciences,P.D.Patel Institute of Applied Sciences,Charotar University of Science and Technology(CHARUSAT),Changa,Anand 388421,Gujarat,India

出  处:《Communications in Theoretical Physics》2023年第7期103-112,共10页理论物理通讯(英文版)

基  金:UGC,New Delhi,India for providing Senior Research Fellowship(UGC-Ref.No.:191620096030);UGC,Govt.of India,New Delhi,for awarding JRF(NTA Ref.No.:191620024300);the Science and Engineering Research Board,Department of Science and Technology,Government of India for financial support to carry out Research Project No.:CRG/2022/001847;IUCAA,Pune,India for providing support through the visiting Associateship program。

摘  要:In this article,we investigate the observed cosmic acceleration in the framework of a cosmological f(R,Lm)model dominated by bulk viscous matter in an anisotropic background.We consider the locally rotationally symmetric Bianchi type I metric and derive the Friedmann equations that drive the gravitational interactions in f((R,Lm)gravity.Further,we assume the functional form f(R,Lm)=R/2+Lαm,where a is a free model parameter,and then find the exact solutions of field equations corresponding to our viscous matter dominated model.We incorporate the updated H(z)data and the Pantheon data to acquire the best-fit values of parameters of our model by utilizing theχ2 minimization technique along with the Markov Chain Monte Carlo random sampling method.Further,we present the behavior of physical parameters that describe the Universe’s evolution phase,such as density,effective pressure and EoS parameters,skewness parameter,and the statefinder diagnostic parameters.We find that the energy density indicates expected positive behavior,whereas the negative behavior of bulk viscous pressure contributes to the Universe’s expansion.The effective EoS parameter favors the accelerating phase of the Universe’s expansion.Moreover,the skewness parameter shows the anisotropic nature of spacetime during the entire evolution phase of the Universe.Finally,from the statefinder diagnostic test,we found that our cosmological f(R,Lm)model lies in the quintessence region,and it behaves like a de-Sitter universe in the far future.We analyze different energy conditions in order to test the consistency of the obtained solution.We find that all energy conditions except strong energy condition(SEC)show positive behavior,while the violation of SEC favors the recently observed acceleration with the transition from decelerated to an accelerated epoch of the Universe’s expansion in the recent past.

关 键 词:LRS Bianchi type I metric f(R Lm)gravity bulk viscosity skewness parameter equation of state parameter statefinder parameter 

分 类 号:P159[天文地球—天文学]

 

参考文献:

正在载入数据...

 

二级参考文献:

正在载入数据...

 

耦合文献:

正在载入数据...

 

引证文献:

正在载入数据...

 

二级引证文献:

正在载入数据...

 

同被引文献:

正在载入数据...

 

相关期刊文献:

正在载入数据...

相关的主题
相关的作者对象
相关的机构对象