220 citations · 904 across the 41 of their papers we have counts for
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An exposition on Friedmann Cosmology with Negative Energy Densities
Robert J. Nemiroff, Ravi Joshi, Bijunath R. Patla
How would negative energy density affect a classic Friedmann cosmology? Although never measured and possibly unphysical, certain realizations of quantum field theories leaves the d…
Incidence of Strong MgII Absorbers Towards Different Types of Quasars
Ravi Joshi, Hum Chand, Gopal-Krishna
We report the first comparative study of strong MgII absorbers seen towards radio-loud quasars of core-dominated (CDQs) and lobe-dominated (LDQs) types and normal QSOs. The MgII as…
Dependence of Residual Rotation Measure (RRM) on Intervening MgII Absorbers at Cosmic Distances
Ravi Joshi, Hum Chand
We investigate the dependence of residual rotation measure (RRM) on intervening absorption systems at cosmic distances by using a large sample of 539 SDSS quasars in conjunction wi…
Intranight Optical Variability of Radio-Quiet Weak Emission Line Quasars
Gopal-Krishna, Ravi Joshi, Hum Chand
Based on a recently started programme, we report the first search for intranight optical variability among radio-quiet weak-line-quasars (RQWLQs). Eight members of this class were…
Probing spectral properties of radio-quiet quasars searched for optical microvariability-II
Ravi Joshi, Hum Chand, Paul J. Wiita +2
In the context of AGN unification scheme rapid variability properties play an important role in understanding any intrinsic differences between sources in different classes. In thi…
Optical microvariability properties of BALQSOs
Ravi Joshi, Hum Chand, Alok C. Gupta +1
We present optical light curves of 19 radio quiet (RQ) broad absorption line (BAL) QSOs and study their rapid variability characteristics. Systematic CCD observations, aided by a c…