13,459 research outputs found
Relativistic quantum motion of spin-0 particles under the influence of non-inertial effects in the cosmic string space-time
We study solutions for the Klein-Gordon equation with vector and scalar
potentials of the Coulomb types under the influence of non-inertial effects in
the space-time of topological defects. We also investigate a quantum particle
described by the Klein-Gordon oscillator in the background space-time generated
by a string. An important result obtained is that the non-inertial effects
restrict the physical region of the space-time where the particle can be
placed. In addition, we show that these potentials can form bound states for
the relativistic wave equation equation in this kind of background.Comment: arXiv admin note: text overlap with arXiv:1608.0669
The role of the time gauge in the 2nd order formalism
We perform a canonical quantization of gravity in a second-order formulation,
taking as configuration variables those describing a 4-bein, not adapted to the
space-time splitting. We outline how, neither if we fix the Lorentz frame
before quantizing, nor if we perform no gauge fixing at all, is invariance
under boost transformations affected by the quantization.Comment: 4 pages, Proceedings of the II Stueckelberg Worksho
Detecting transit signatures of exoplanetary rings using SOAP3.0
CONTEXT. It is theoretically possible for rings to have formed around
extrasolar planets in a similar way to that in which they formed around the
giant planets in our solar system. However, no such rings have been detected to
date.
AIMS: We aim to test the possibility of detecting rings around exoplanets by
investigating the photometric and spectroscopic ring signatures in
high-precision transit signals.
METHODS: The photometric and spectroscopic transit signals of a ringed planet
is expected to show deviations from that of a spherical planet. We used these
deviations to quantify the detectability of rings. We present SOAP3.0 which is
a numerical tool to simulate ringed planet transits and measure ring
detectability based on amplitudes of the residuals between the ringed planet
signal and best fit ringless model.
RESULTS: We find that it is possible to detect the photometric and
spectroscopic signature of near edge-on rings especially around planets with
high impact parameter. Time resolution 7 mins is required for the
photometric detection, while 15 mins is sufficient for the spectroscopic
detection. We also show that future instruments like CHEOPS and ESPRESSO, with
precisions that allow ring signatures to be well above their noise-level,
present good prospects for detecting rings.Comment: 13 pages, 16 figures, 2 tables , accepted for publication in A&
Non-Euclidean ideal spectrometer
We describe the mathematical scheme for an anomaly-free ideal spectrometer,
based on a 2-dimensional plane medium with conical regions of bounded slope.
Moreover, the construction may be realised in many different configurations.Comment: 9 pages, 5 figure
The Causal Interpretation of Quantum Mechanics and The Singularity Problem in Quantum Cosmology
We apply the causal interpretation of quantum mechanics to homogeneous
quantum cosmology and show that the quantum theory is independent of any
time-gauge choice and there is no issue of time. We exemplify this result by
studying a particular minisuperspace model where the quantum potential driven
by a prescribed quantum state prevents the formation of the classical
singularity, independently on the choice of the lapse function. This means that
the fast-slow-time gauge conjecture is irrelevant within the framework of the
causal interpretation of quantum cosmology.Comment: 18 pages, LaTe
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