AUTHOR=Ray Pranjal Kumar , Roy Baruah Rajshekhar 

TITLE=Anisotropic cloud string cosmological model with five-dimensional kaluza-klein space-time

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2022.869020

DOI=10.3389/fspas.2022.869020

ISSN=2296-987X

ABSTRACT=<p>Anisotropic cloud string cosmological models has been investigated in the context of five dimensional Kaluza- Klein space time. In this paper the energy momentum tensor is generated by rest energy density and tension density of the string with particle density attached to them. To obtained the exact solutions of the Einstein field equations we assumed a scale factor <inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>a</mml:mi><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mi>t</mml:mi></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mfrac><mml:mrow><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>β</mml:mi></mml:mrow></mml:mfrac><mml:msqrt><mml:mrow><mml:mn>2</mml:mn><mml:mi>β</mml:mi><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mi>c</mml:mi></mml:mrow></mml:msqrt></mml:mrow></mml:msup></mml:math></inline-formula> where <italic>β</italic> and <italic>c</italic> are positive constant, which yields a variable deceleration parameter (DP) <inline-formula id="inf2"><mml:math id="m2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>q</mml:mi><mml:mo>=</mml:mo><mml:mo>−</mml:mo><mml:mfrac><mml:mrow><mml:mi>a</mml:mi><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>a</mml:mi></mml:mrow><mml:mo>̈</mml:mo></mml:mover></mml:mrow></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>a</mml:mi></mml:mrow><mml:mo>̇</mml:mo></mml:mover></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:mfrac><mml:mo>=</mml:mo><mml:mi>β</mml:mi><mml:mi>H</mml:mi><mml:mo>+</mml:mo><mml:mi>α</mml:mi></mml:math></inline-formula>. The physical and geometrical behavior of the models is also discussed in detail.</p>