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Chandel, India

Meitei I.A.,Pettigrew College | Singh T.I.,United College | Singh K.Y.,Manipur University
International Journal of Modern Physics D | Year: 2014

Using the Hamilton-Jacobi method a study of quantum nonthermal radiation of nonstationary rotating de Sitter cosmological model is carried out. It is shown that there exist seas of positive and negative energy states in the vicinity of the cosmological event horizon and there also exists a forbidden energy gap between the two seas. The forbidden energy gap vanishes on the surface of the cosmological event horizon so that the positive and negative energy levels overlap. The width of the forbidden energy gap and the energy of the particle at the cosmological event horizon are found to depend on the cosmological constant, the rotation parameter, positions of the particle and the cosmological event horizon, angular momentum of the particle, evaporation rate and shape of the cosmological event horizon. The tunneling probability of the emitted particles constituting Hawking radiation is also deduced for stationary nonrotating de Sitter cosmological model and the standard Hawking temperature is recovered. © 2014 World Scientific Publishing Company. Source


Ibungochouba Singh T.,United College | Ablu Meitei I.,Pettigrew College | Yugindro Singh K.,Manipur University
Astrophysics and Space Science | Year: 2013

Hawking radiation of Kerr-de Sitter black hole is investigated using Hamilton-Jacobi method. When the well-behaved Painleve coordinate system and Eddington coordinate are used, we get the correct result of Bekenstein-Hawking entropy before and after radiation but a direct computation will lead to a wrong result via Hamilton-Jacobi method. Our results show that the tunneling probability is related to the change of Bekenstein-Hawking entropy and the derived emission spectrum deviates from the pure thermal but it is consistent with underlying unitary theory. © 2013 Springer Science+Business Media Dordrecht. Source


Ibohal N.,Manipur University | Ibungochouba T.,United College
Astrophysics and Space Science | Year: 2013

Hawking's radiation effect of Klein-Gordon equation, Dirac particles and Maxwell's electromagnetic fields in the non-stationary rotating de Sitter cosmological space-time is investigated by using a new method of generalized tortoise coordinate transformation. It is found that the new transformation produces constant additional terms in the expressions of the surface gravities and the Hawking's temperatures. If the constant terms are set to zero, then the surface gravities and Hawking's temperatures will be equal to those obtained from the old generalized tortoise coordinate transformations. This shows that the new transformations are more reasonable. The Fermionic spectrum of Dirac particles displays a new spin-rotation coupling effect. © 2012 Springer Science+Business Media B.V. Source


Ibungochouba Singh T.,United College | Ablu Meitei I.,Pettigrew College | Yugindro Singh K.,Manipur University
Astrophysics and Space Science | Year: 2014

The entropy correction of Kerr-Newman black hole is investigated using the Hamilton-Jacobi method beyond semiclassical approximation. To get entropy correction, the inverse of the sum of square of event horizon (r +) and the square of rotational parameter a of the black hole is taken as the proportionality parameter for quantum corrections of the action I i to the semiclassical action I 0. It has been shown that as quantum effects are taken into account the corrections to the Bekenstein-Hawking entropy of the stationary black hole include a logarithmic term and an inverse area term beyond the semiclassical approximation. © 2014 Springer Science+Business Media Dordrecht. Source


Rajkumar H.S.,United College | Mustoe G.E.,Western Washington University | Soibam I.,Manipur University
Ichnos:an International Journal of Plant and Animal | Year: 2015

A marine tidal delta siltstone from Gelmon locality in Northeast India preserved three crocodylian footprints and an elongate depression that appears to be a tail drag mark. Similar drag marks occur in nearby bedding surfaces. The discovery of crocodylian tracks from the basal part of Laisong Formation, Barail Group (Late Eocene–Early Oligocene age) of Manipur, India is noteworthy because of the age and the geographic location. Crocodylian tracks are rare in Cenozoic formations and they have not previously been reported from Asia. The footprints are herein named as a new ichnogenus and ichnospecies, Indosuchipes manipurensis. © 2015, Copyright © Taylor & Francis Group, LLC. Source

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