TITLE:
Accelerated Universe with Bulk Viscous Fluid in f(R, T) Gravity
AUTHORS:
Rishi Kumar Tiwari, Aroon Beesham, Murleedhar Pal
KEYWORDS:
Bianchi Type-V, Space-Time, Modified Gravity, Non-Minimal Coupling, Anisotropic Cosmology, Scale Factor
JOURNAL NAME:
Journal of Applied Mathematics and Physics,
Vol.14 No.9,
September
30,
2026
ABSTRACT: In this work, we examine an anisotropic Bianchi type-V cosmological model in the framework of modified
f(
R,T
)
gravity, adopting the non-minimal coupling form
f(
R,T
)=
f
1
(
R
)+
f
2
(
R
)
f
3
(
T
)
where R is the Ricci scalar and T is the trace of the energy-momentum tensor. The gravitational field equations are derived for a perfect fluid with barotropic equation of state p = ζρ and solved by assuming an appropriate law of variation for the mean scale factor that incorporates the deceleration parameter. In contrast to previous studies that used an incorrect exponent form, we construct the average scale factor as
a=
(
e
cnT
−d
c
)
1
n
. Here n, c, d are constants, ensuring a physically consistent transition from an early decelerating phase to late-time acceleration that aligns with current cosmological observations. In this work, we extend the bulk viscous Bianchi type-V cosmological model in
f(
R,T
)
gravity previously studied by Bhardwaj et al. (2019) by introducing a new exponential-type shifted scale factor. The directional scale factors and physical quantities such as the Hubble rates, expansion and shear scalars are obtained explicitly, revealing that the model universe evolves from a highly anisotropic state toward isotropy at late times. The behavior of the effective equation of state and cosmological parameters indicate that the present accelerated expansion can be effectively realized within this model without requiring a cosmological constant term. The influence of the non-minimal coupling in the
f(
R,T
)
function on the dynamical evolution, anisotropy decay, and energy conditions is analyzed in detail. Our findings are consistent with recent investigations of Bianchi type-V universes in modified gravity theories and provide new insights for further theoretical and observational studies.