Topological defects in f(T) theory of gravity

Abstract In this paper, we investigate the behaviour of domain walls and one-dimensional cosmic string with locally rotationally symmetric (LRS) Bianchi type-I metric in the context of f ( T ) gravity. Three different types of deceleration parameter (DP) forms, such as (i) $$q=-kt+l-1$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>q</mml:mi> <mml:mo>=</mml:mo> <mml:mo>-</mml:mo> <mml:mi>k</mml:mi> <mml:mi>t</mml:mi> <mml:mo>+</mml:mo> <mml:mi>l</mml:mi> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> , (ii) $$q=b(t)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>q</mml:mi> <mml:mo>=</mml:mo> <mml:mi>b</mml:mi> <mml:mo>(</mml:mo> <mml:mi>t</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> , and (iii) $$q=-1+\frac{\gamma }{1+a^\gamma }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>q</mml:mi> <mml:mo>=</mml:mo> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> <mml:mfrac> <mml:mi>γ</mml:mi> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> <mml:msup> <mml:mi>a</mml:mi> <mml:mi>γ</mml:mi> </mml:msup> </mml:mrow> </mml:mfrac> </mml:mrow> </mml:math> , are used to determine the exact solution of the field equation. We observe the profound effect of the torsion scalar T on physical parameters. Also, the universe was dominated by string at an early stage of evaluation.