11 papers · 1 filter
Gravitational capture cross-section in Zipoy-Voorhees spacetimes
Serzhan Momynov, Kuantay Boshkayev, Hernando Quevedo +5
We consider geodesics of massive and massless test particles in the gravitational field of a static and axisymmetric compact object described by the quadrupolar metric (-metric)…
On the single versus the repetitive Penrose process in a Kerr black hole
Remo Ruffini, Mikalai Prakapenia, Hernando Quevedo +1
Extracting the rotational energy from a Kerr black hole (BH) is one of the crucial topics in relativistic astrophysics. Here, we give special attention to the Penrose ballistic pro…
Event horizons under the effect of the Penrose process
Hernando Quevedo
We investigate how test particles absorbed by a black hole affect the properties of the event horizon. We consider particles that arrive from infinity with positive energy and cros…
Spherically symmetric collapse: Initial configurations
Elly Bayona, Hernando Quevedo, Miguel Alcubierre
The initial state of the spherical gravitational collapse in general relativity has been studied with different methods, especially by using {\it a priori} given equations of state…
Time is entropy: A geometric proof
Hernando Quevedo
We analyze the equilibrium space of an ideal gas using the formalism of geometrothermodynamics. We introduce the concept of thermodynamic geodesics to show that the equilibrium spa…
Functional measures associated to operators
Luis A. Cedeño-Pérez, Hernando Quevedo
We show that every operator in has an associated measure on a space of functions and prove that it can be used to find solutions to abstract Cauchy problems, including part…