Associate Professor and Head, Zonuam, Aizawl http://pucir.inflibnet.ac.in:8080/jspui/handle/123456789/224 2026-04-30T21:10:15Z 2026-04-30T21:10:15Z Lalvohbika, J http://pucir.inflibnet.ac.in:8080/jspui/handle/123456789/1058 2025-10-21T06:18:50Z 2024-03-01T00:00:00Z

Title: Casimir wormhole solutions in 𝑓(𝑅,𝑚 ) gravity Authors: Lalvohbika, J Abstract: In this paper, we study the Casimir effect on the wormhole geometry in 𝑓(𝑅,𝑚 ) gravity. We derive the field equations for the generic 𝑓(𝑅,𝑚 ) function by assuming static and spherically symmetric Morris–Thorne wormhole metric. Then we consider two non-linear 𝑓(𝑅,𝑚 ) models, specifically, 𝑓(𝑅,𝑚 ) = 𝑅 2 + 𝛽 𝑚 and 𝑓(𝑅,𝑚 ) = 𝑅 2 +(1+𝛼𝑚 )𝑚 where 𝛼 and 𝛽 are free parameters. We derive the shape functions for wormholes by utilizing the Casimir effect and examining their existence. Subsequently, we analyse the obtained wormhole solutions for each scenario, assessing the energy conditions at the wormhole throat with a radius of 𝑟0 . Our findings reveal that for some arbitrary quantities, there is a violation of classical energy conditions at the wormhole throat. Additionally, we delve into the behaviour of the equation of state (EoS) for each case. Furthermore, we explore the stability of the Casimir effect wormhole solutions by employing the generalized Tolman–Oppenheimer–Volkoff (TOV) equation. Finally, we utilize the volume integral quantifier to determine the amount of exotic matter required near the wormhole throat for both models.

2024-03-01T00:00:00Z Lalvohbika, J http://pucir.inflibnet.ac.in:8080/jspui/handle/123456789/1057 2025-10-21T06:16:31Z 2020-04-15T00:00:00Z

Title: Scattering of qSH-waves from a corrugated interface between two dissimilar nematic elastomers Authors: Lalvohbika, J Abstract: This paper aims to investigate the reflection and transmission phenomena of elastic waves due to incident qSH-wave at a corrugated interface between two different nematic elastomer half-spaces. The expression of the phase velocity for shear harmonic wave is derived and observed that this phase velocity depends on the angle of propagation. There exist irregularly reflected and transmitted waves besides the regular waves due to undulated nature of the interface whose nth spectrum is related through Spectrum theorem. The amplitude ratios for various reflected and transmitted waves are derived using boundary conditions. The ratios corresponding to an irregular waves arefound to befunctions of the incident angle, elastic constants, relaxation times, corrugation and frequency parameters. The energy distribution, and hence the energy ratios due to various reflected and transmitted waves are also obtained. It is observed that the sum of all energy ratios is approximately unity at each value of incident angle which ensures the law of conservation of energy at the interface. A particular case, z = d cos px has been performed to validate the present study for the amplitude and energy ratios. Graphs are plotted for these ratios at different values of corrugation and frequency parameters to discuss their effects.

2020-04-15T00:00:00Z Lalvohbika, J http://pucir.inflibnet.ac.in:8080/jspui/handle/123456789/783 2024-06-18T06:30:43Z 2021-01-01T00:00:00Z

Title: THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY J. LALVOHBIKA Authors: Lalvohbika, J Abstract: THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY J. LALVOHBIKA

2021-01-01T00:00:00Z Lalvohbika, J Lalvohbika, J http://pucir.inflibnet.ac.in:8080/jspui/handle/123456789/782 2024-06-18T06:27:18Z 2014-01-01T00:00:00Z

Title: SCATTERING OF ELASTIC WAVES FROM A CORRUGATED INTERFACE; SCATTERING OF ELASTIC WAVES FROM A CORRUGATED INTERFACE Authors: Lalvohbika, J; Lalvohbika, J Abstract: THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY J. LALVOHBIKA

2014-01-01T00:00:00Z