Ghosh, Sankha (1932–)

Bhattacharya, Sourin

doi:10.4324/9781135000356-rem1502-1

Cited by 3 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These correspond to different quantum theories built from the same classical theory. Different quantum theories can be constructed without violating gauge invariance by changing the definition of the point split fermionic currents [9,10]. By considering this freedom, we shall demonstrate that the problem of information loss can in fact appear even in the extremal magnetically charged black hole in a dilatonic background.…”

mentioning

confidence: 93%

“…where Φ(y) is a nondynamical function of spacetime coordinates which we shall fix later on. The addition of a term containing this function in the exponent represents a generalization of Schwinger's regularizing phase factor [9,10]. It preserves gauge invariance, Lorentz invariance and even the linearity of the theory.…”

mentioning

confidence: 99%

“…However, his choice was only one of many possible choices; see, e.g. [9,10]. We have inserted an extra factor which involves the field strength of the gauge field and a nondynamical function of spacetime coordiantes and therefore does not interfere with the gauge invariance of the product.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Fermion scattering off dilatonic black holes

Ghosh

Mitra

1994

Phys. Rev. D

View full text Add to dashboard Cite

The scattering of massless fermions off magnetically charged dilatonic black holes is reconsidered and a violation of unitarity is found. Even for a single species of fermion it is possible for a particle to disappear into the black hole with its information content.In recent years there has been a lot of interest in the physics of black holes. The issue which has engaged the attention of most workers is that of possible information loss. Matter falling into a black hole carries some information with it. This becomes inaccessible to the rest of the world, but may in principle be supposed to be stored inside the black hole in some sense. A problem arises when the black hole evaporates through the process of Hawking radiation. The information does seem to be lost now [1].Although there have been attempts at studying this problem in its full complexity [2], most authors have considered simplified models of black holes as in [3,4]; see [5] for a review. We shall consider the extremal magnetically charged black hole solution of dilatonic gravity. This is a four dimensional model involving an extra field -the dilaton -but for s-wave scattering of particles in the field of this black hole, the angular coordinates are not relevant and a two dimensional 1 e-mail mitra@saha.ernet.in 1

show abstract

mentioning

confidence: 93%

mentioning

confidence: 99%

See 1 more Smart Citation

Fermion scattering off dilatonic black holes

Ghosh

Mitra

1994

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…Due to the involvement of the associated charged components of the two IHDs, the typical opposite sign di-lepton plus missing energy signature can be quite interesting at LHC [128].…”

Section: Furthermore We Consider M Hmentioning

confidence: 99%

Minimal two-component scalar doublet dark matter with radiative neutrino mass

2019

View full text Add to dashboard Cite

We propose a minimal extension of the Standard Model to accommodate two-component dark matter (DM) and light neutrino mass. The symmetry of the Standard Model is enhanced by an unbroken Z 2 × Z 2 such that being odd under each Z 2 , there exists one right handed neutrino and one inert scalar doublet. Therefore, each of the Z 2 sectors contribute to (i) light neutrino masses radiatively similar to the scotogenic models while (ii) the two neutral CP even scalars present in two additional inert doublets play the role of dark matters. Focussing on the intermediate range of inert scalar doublet DM scenario: M W ≤ M DM 500 GeV, where one scalar doublet DM can not satisfy correct relic, we show that this entire range becomes allowed within this two-component scalar doublet DM, thanks to the inter-conversion between the two DM candidates in presence of neutrino Yukawa couplings with dark sector.

show abstract

“…That is two clustering may be same except for a permutation of the components. a methodology introduced by Bhattacharya(2009) to tackle such difficulties. The methodology of Bhattacharya(2009) relies on an appropriately defined metric to compute distances between any two clusterings of a given data set.…”

Section: Bayesian Posterior Distribution Of Clusteringmentioning

confidence: 99%

Fast and efficient Bayesian semi-parametric curve-fitting and clustering in massive data

2012

View full text Add to dashboard Cite

Recent technological advances have led to a flood of new data on cosmology rich in information about the formation and evolution of the universe, e.g., the data collected in Sloan Digital Sky Survey (SDSS) for more than 200 million objects. The analyses of such data demand cutting edge statistical technologies. Here, we have used the concept of mixture model within Bayesian semiparametric methodology to fit the regression curve with the bivariate data for the apparent magnitude and redshift for Quasars in SDSS (2007) catalogue. Associated with the mixture modeling is a highly efficient curve-fitting procedure, which is central to the application considered in this paper. Moreover, we adopt a new method for analysing the posterior distribution of clusterings, also generated as a by-product of our methodology. The results of our analysis of the cosmological data clearly indicate the existence of four change points on the regression curve and posssibiltiy of clustering of quasars specially at high redshift. This sheds new light not only on the issue of evolution, existence of acceleration or decceleration and environment around quasars at high redshift but also help us to estimate the cosmological parameters related to acceleration or decceleration.

show abstract

Ghosh, Sankha (1932–)

Cited by 3 publications

References 0 publications

Fermion scattering off dilatonic black holes

Fermion scattering off dilatonic black holes

Minimal two-component scalar doublet dark matter with radiative neutrino mass

Fast and efficient Bayesian semi-parametric curve-fitting and clustering in massive data

Contact Info

Product

Resources

About