4 citations · 4 across the 6 of their papers we have counts for
6 papers
A Complete Invariant Analysis of the Kerr Spacetime and its Photon Region
Nicholas Layden, Dipanjan Dey, Alan Coley
We present an invariant characterization of the Kerr spacetime, and utilize the invariant structure of the spacetime to derive a function whose zeros identify a special family of n…
The Definition of a Photon Surface in an Invariant Spin Frame
Dipanjan Dey, Alan A. Coley, Nicholas T. Layden
This paper defines the photon surface conditions using Cartan scalars within an invariant spin frame, offering a comprehensive description of the local spacetime geometry. By emplo…
Invariant description of static and dynamical Brans-Dicke spherically symmetric models
Nicholas Layden, Alan Coley, Dipanjan Dey
We investigate spherically symmetric static and dynamical Brans-Dicke theory exact solutions using invariants and, in particular, the Newman Penrose formalism utilizing Cartan scal…
The equilibrium condition in gravitational collapse and its application to a cosmological scenario
Dipanjan Dey, N. T. Layden, A. A. Coley +1
We discuss the equilibrium conditions of the gravitational collapse of a spherically symmetric matter cloud. We analyze the spinor structure of a general collapsing space-time and…
An invariant characterization of the quasi-spherical Szekeres dust models
A. A. Coley, N. Layden, D. D. McNutt
The quasi-spherical Szekeres dust solutions are a generalization of the spherically symmetric Lemaitre-Tolman-Bondi dust models where the spherical shells of constant mass are non-…
NLTE and LTE Lick indices for red giants from [M/H] 0.0 to -6.0 at SDSS and IDS spectral resolution
C. Ian Short, Mitchell E. Young, Nicholas Layden
We investigate the dependence of the complete system of 22 Lick indices on overall metallicity scaled from solar abundances, [M/H], from the solar value, 0.0, down to the extremely…