Articles written in Pramana – Journal of Physics
Volume 52 Issue 1 January 1999 pp 1-17
We consider particle production in Robertson-Walker spacetime as particle-antiparticle rotation. We thereby obtain a scale factor that guarantees particle production. We then study quantum field effects in spatially flat homogeneous and isotropic spacetime with energy density of created particles and one loop quantum correction as back reaction. In the numerical solution initial values are determined from particle production simulated scale factor and obtain the evolution of the universe both at early and late times having a bounce.
Volume 62 Issue 6 June 2004 pp 1231-1239
We discuss the method of calculating the reflection coefficient using complex trajectory WKB (CWKB) approximation to understand the non-reflecting nature of the potential
Volume 68 Issue 1 January 2007 pp 1-19 Research Articles
We present the calculation of envelope of boson and of both low- and high- mass fermion production at the end of inflation when the coherently oscillating inflatons decay into bosons and fermions. We consider three different models of inflation and use CWKB technique to calculate the envelope to understand the structure of resonance band formation. We observe that though low-mass fermion production is not effective in pre-heating because of Pauli blocking, it is quite probable for high-mass fermion to take part in pre-heating.
Volume 85 Issue 3 September 2015 pp 395-402
The time-stamp structure of the digital data acquisition system of the Indian National Gamma Array (INGA) has been utilized to carry out prompt-delayed coincidence technique for the spectroscopic study of fission fragments. This technique was found to be useful to determine the states above the long-lived isomer (with half-life up to $\sim$5 𝜇s), present in the fission fragments. The angular correlation of 𝛾-rays, emitted by the fission fragments, has also been used in the present INGA geometry to determine the spins of the de-exciting states.
Volume 94, 2020
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