Person: Jannes, Gil
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First Name
Gil
Last Name
Jannes
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Económicas y Empresariales
Department
Economía Financiera, Actuarial y Estadística
Area
Estadística e Investigación Operativa
Identifiers
3 results
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Now showing 1 - 3 of 3
Item The trans-Planckian problem as a guiding principle(Journal of high energy physics, 2011) Barbado, L. C.; Barceló, C.; Garay Elizondo, Luis Javier; Jannes, GilWe use the avoidance of the trans-Planckian problem of Hawking radiation as a guiding principle in searching for a compelling scenario for the evaporation of black holes or black-hole-like objects. We argue that there exist only three possible scenarios, depending on whether the classical notion of long-lived horizon is preserved by high-energy physics and on whether the dark and compact astrophysical objects that we observe have long-lived horizons in the first place. Along the way, we find that i) a theory with high-energy superluminal signalling and a long-lived trapping horizon would be extremely unstable in astrophysical terms and that i i) stellar pulsations of objects hovering right outside but extremely close to their gravitational radius can result in a mechanism for Hawking-like emission.Item Hawking versus Unruh effects, or the difficulty of slowly crossing a black hole horizon(Journal of High Energy Physics, 2016) Barbado, Luis C.; Barceló, Carlos; Garay Elizondo, Luis Javier; Jannes, GilWhen analyzing the perception of Hawking radiation by different observers, the Hawking effect becomes mixed with the Unruh effect. The separation of both effects is not always clear in the literature. Here we propose an inconsistency-free interpretation of what constitutes a Hawking effect and what an Unruh effect. An appropriate interpretation is important in order to elucidate what sort of effects a detector might experience depending on its trajectory and the state of the quantum field. Under simplifying assumptions we introduce an analytic formula that separates these two effects. Armed with the previous interpretation we argue that for a free-falling detector to cross the horizon without experiencing high-energy effects, it is necessary that the horizon crossing is not attempted at low velocities.Item Quantum non-gravity and stellar collapse(Foundations of physics, 2011) Barceló, Carlos; Garay Elizondo, Luis Javier; Jannes, GilObservational indications combined with analyses of analogue and emergent gravity in condensed matter systems support the possibility that there might be two distinct energy scales related to quantum gravity: the scale that sets the onset of quantum gravitational effects E-B ( related to the Planck scale) and the much higher scale E-L signalling the breaking of Lorentz symmetry. We suggest a natural interpretation for these two scales: E-L is the energy scale below which a special relativistic spacetime emerges, E-B is the scale below which this spacetime geometry becomes curved. This implies that the first 'quantum' gravitational effect around E-B could simply be that gravity is progressively switched off, leaving an effective Minkowski quantum field theory up to much higher energies of the order of E-L. This scenario may have important consequences for gravitational collapse, inasmuch as it opens up new possibilities for the final state of stellar collapse other than an evaporating black hole.