The ring-down phase of black-hole perturbations is governed by the quasi-normal modes (QNM) and offer valuable insight into the nature of the objects emitting them, raising an interesting question: whether QNM5 can be used to distinguish between theories of gravity? We construct a consistency test of general relativity (GR) which enables one to dis...

Reheating phase of inflationary Universe can be modeled by parameters T-reh, (omega) over bar (reh) and N-reh, which can be constrained by the scalar spectral amplitude A(s) and the scalar spectral index n(s). On the other hand the low multipole anomalies in the CMB can be modeled by suitable features in the inflaton potential. We show that the par...

Given a Hilbert space , we investigate the well-posedness of the Cauchy problem for the wave equation for operators with a discrete non-negative spectrum acting on . We consider the cases when the time-dependent propagation speed is regular, Holder, and distributional. We also consider cases when it is strictly positive (strictly hyperbolic case) a...

In this paper, we study the Cauchy problem for the Landau Hamiltonian wave equation, with time-dependent irregular (distributional) electromagnetic field and similarly irregular velocity. For such equations, we describe the notion of a 'very weak solution' adapted to the type of solutions that exist for regular coefficients. The construction is bas...

Allen, R. J.Norris, J. R.Sherwood, S. C.Zender, C. S.

Several recent studies have shown the width of the tropical belt has increased over the last several decades. The mechanisms driving tropical expansion are not well known and the recent expansion is underpredicted by state-of-the art GCMs. We use the CAM3 GCM to investigate how tropical width responds to idealized atmospheric heat sources, focusing...