Subhra Bhattacharya
Subhasis Nalui
Journal of Mathematical Physics
2023
🔬 Research Highlights
We introduce a complexity factor parametrization for static traversable wormholes based on Herrera’s definition for spherically symmetric self-gravitating systems.
A general polynomial complexity framework is developed, providing an analytical method to construct physically viable traversable wormhole geometries.
We demonstrate that zero-complexity wormholes are not admissible under the essential conditions of asymptotic flare-out and absence of horizons.
The resulting non-zero complexity configurations naturally lead to Casimir-like traversable wormholes, where the choice of logarithmic tidal function and polynomial complexity factor yields solutions supported by anisotropic exotic matter with physically consistent radial equation-of-state behaviour near the throat.
Journal Article:
https://doi.org/10.1063/5.0148762
arXiv:
Subhasis Nalui
Subhra Bhattacharya
Annals of Physics
📅 Year
2024
🔬 Research Highlights
Developed a time-dependent Morris–Thorne wormhole model with radial heat flux and matched it to the exterior Vaidya spacetime via junction conditions.
Derived the full dynamical collapse equation for an inhomogeneous, anisotropic, shear-free dissipative matter distribution.
Identified four distinct classes of solutions (S1–S4) leading to qualitatively different end states.
Demonstrated that collapse to zero proper volume in finite time inevitably forms a black-hole–type singularity.
Revealed rich alternative outcomes including wormhole–black hole transition, oscillating wormhole–black hole pair, conformal big-crunch–type collapse, and infinite-time contraction.
Analyzed stability using the complexity factor formalism, identifying simple (stable) and dynamically rich configurations.
Journal Article:
https://doi.org/10.1016/j.aop.2024.169789
arXiv:
Subhasis Nalui
Subhra Bhattacharya
Physics Letters B
2025
🔬 Research Highlights
Established a direct connection between the Herrera complexity factor and the formation and stability of photon spheres in static, spherically symmetric compact objects.
Demonstrated that zero-complexity configurations do not support photon spheres or shadows.
Expressed the complexity factor purely in terms of geometric (metric) variables, directly linking spacetime structure with null geodesics and observable shadow radius.
Provided a physical interpretation of spacetime complexity in terms of light-ring stability and gravitational observables.
Journal Article:
https://doi.org/10.1016/j.physletb.2025.139261
arXiv:
Subhasis Nalui
Subhra Bhattacharya
The Eueopean Physical Journal C
2025
Constructed four independent Morris–Thorne wormhole solutions in metric f(R) gravity using a novel linear equation of state for inhomogeneous matter.
Identified geometries with solid angle deficit, asymptotic extendibility, and zero tidal force, including the simplest traversable wormhole configuration.
Demonstrated that the models admit both NEC-satisfying and NEC-violating regimes; non-exotic wormholes require ghost-like f(R).
Established cosmological viability of the derived power-law f(R) models and provided scalar–tensor interpretation via equivalence with Brans–Dicke theory. The robustness of the wormhole solutions were further analysed with the BD scalar fields in the hybrid metric-Palatini gravity, which showed excellent results.
Showed that the relation between the Herrera complexity factor and photon sphere formation remains unchanged in f(R) gravity compared to Einstein gravity, strengthening its astrophysical relevance.
Journal Article:
https://doi.org/10.1140/epjc/s10052-025-14863-x
arXiv: