Curvature Inspired Cosmological Scenario

Using modified gravity with non-linear terms of curvature, $R^2$ and $R^{(r +2)}$ (with $r$ being the positive real number and $R$ being the scalar curvature), cosmological scenario,beginning at the Planck scale, is obtained. Here, a unified picture of cosmology is obtained from $f(R)-$ gravity. In this scenario, universe begins with power-law inflation, followed by deceleration and acceleration in the late universe as well as possible collapse of the universe in future. It is different from $f(R)-$ dark energy models with non-linear curvature terms assumed as dark energy. Here, dark energy terms are induced by linear as well as non-linear terms of curvature in Friedmann equation being derived from modified gravity.It is also interesting to see that, in this model, dark radiation and dark matter terms emerge spontaneously from the gravitational sector. It is found that dark energy, obtained here, behaves as quintessence in the early universe and phantom in the late universe. Moreover, analogous to brane-tension in brane-gravity inspired Friedmann equation, a tension term $\lambda$ arises here being called as cosmic tension. It is found that, in the late universe, Friedmann equation (obtained here) contains a term $- \rho^2/2\lambda$ ($\rho$ being the phantom energy density) analogous to a similar term in Friedmann equation with loop quantum effects, if $\lambda > 0$ and brane-gravity correction when $\lambda < 0.$Comment: 19 Pages. To appear in Int. J. Thro. Phy

Entanglement dynamics following a sudden quench: an exact solution

We present an exact and fully analytical treatment of the entanglement dynamics for an isolated system of $N$ coupled oscillators following a sudden quench of the system parameters. The system is analyzed using the solutions of the time dependent Schrodinger's equation, which are obtained by solving the corresponding nonlinear Ermakov equations. The entanglement entropies exhibit a multi-oscillatory behaviour, where the number of dynamically generated time scales increases with $N$. The harmonic chains exhibit entanglement revival and for larger values of $N (> 10)$, we find near-critical logarithmic scaling for the entanglement entropy, which is modulated by a time dependent factor. The $N=2$ case is equivalent to the two site Bose-Hubbard model in the tunneling regime, which is amenable to empirical realization in cold atom systems.Comment: Figure for large N added, discussion related with near critical scaling behavior adde

Incidence of Agromyza obtusa Malloch in different varieties of Arhar (Cajanus cajan) (Diptera: Agromyzidae).

Aus unseren Beobachtungen geht klar hervor, dass das stärkste Vorkommen von Agromyza obtusa Malloch bei den frühen Varietäten von Cajanus cajan im Dezember und bei den späten Varietäten im März festzustellen ist.The above observations clearly indicatet that the maximum incidence of Agromyza obtusa Malloch was recorded during the month December in early varieties and March in late varieties of Cajanus cajan

Assessment of Earthquake Size from Rock Fracture Dimensions of Seismic Source in Geotechnical Earthquake Engineering Investigations

The paper presents two case histories of rock fractures resulting in strong ground motion. Case I describes the November 27, 1971 rock burst involving 270 m long rupture with displacement of 15 mm in Nundydroog mine in Kolar Gold Field in Karnataka State, India, which resulted in damage to buildings on the surface and underground works in the mine. The event was recorded as an earthquake by seismic stations and the computed magnitude ml = 3.9 of the rockburst compares well with magnitude mb= 4.6 determined from the recorded seismogram. Case II describes April 5, 1976 rock burst in an open cast granite quarry at Shravanbelagola, in Hassan district in Karnataka State, resulting in 60 m long fracture with estimated average displacement of 0.5 mm. The rockburst accompanied with loud noise produced strong ground motion in the area. The magnitude of the rockburst is estimated as ml= 2. The estimated intensity of ground motion in the area match well with the ground motion at the epicentre of an earthquake of similar magnitude. The two studies provide guidelines for assessment of earthquake size and indicates the importance of detection and delineation of tectonic lineaments and determination of ambient seismic activity along lineaments which are capable or have potential for earthquake occurrence

Thermodynamic properties of interstitial elements in the refractory metals Progress report, 1 Jun. - 30 Nov. 1969

Thermodynamic properties of carbon in molybdenum and tungsten at solubility limi

Thermodynamic properties of interstitial elements in the refractory metals Semiannual report, 1 Dec. 1968 - 31 May 1969

Carbon activity in refractory metal

Velocity of sound in relativistic heavy-ion collisions

We have studied the rapidity distribution of secondary hadrons produced in nucleus-nucleus collisions at ultra-relativistic energies within the ambit of the Landau's hydrodynamical model. A reasonable description of the data can also be obtained by using the Bjorken's hydrodynamical model if the boost invariance is restricted to a finite rapidity range. The sensitivity of the hadronic spectra on the equation of state vis- a -vis the velocity of sound has been discussed. The correlation between the velocity of sound and the freeze-out temperature has been indicated. The effects of the non-zero widths of various mesonic and baryonic degrees of freedom up to the mass value ~ 2.5 GeV is seen to be small.Comment: 9 pages and 11 figures. Major changes. To appear in Physical Review

Landau Ghosts and Anti-Ghosts in Condensed Matter and High Density Hadronic Matter

It is observed that the ``ghost'' (originally discovered by Landau in quantum electro-dynamics) and its counterparts in other theories are indeed ubiquitous as they occur in a one-loop approximation to any conventional (unbroken) gauge theory. The mechanism is first exposed in its generality via the Dyson equation and a simple but explicit example in condensed matter is provided through the static Clausius-Mossotti and its dynamic counterpart the Lorenz-Lorentz equation. The physical phase transition phenomenon associated with it is found to be super-radiance. We verify quantitatively that water (and many other polar liquids) are indeed super-radiant at room temperature. In quantum chromo-dynamics on the other hand, we encounter, thanks to asymptotic freedom, an ``anti-ghost'' which is closely associated with color confinement. Thus, in QCD, free quarks and glue exist in a super-radiant phase and hadronic matter in the normal one.Comment: LaTeX 12 Pages and 2 *.eps Figure