14,644 research outputs found
Clifford, William Kingdon
W.K. Clifford’s famous 1876 essay The Ethics of Belief contains one of the most memorable lines in the history of philosophy: "it is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence." The challenge to religious belief stemming from this moralized version of evidentialism is still widely discussed today
Sceptical Theism and the Paradox of Evil
Given plausible assumptions about the nature of evidence and undercutting defeat, many believe that the force of the evidential problem of evil depends on sceptical theism’s being false: if evil is..
k-essence and extended tachyons in brane-worlds
We study a k-essence field evolving linearly with the cosmic time and the
atypical k-essence model on a homogeneous and isotropic flat 3-brane. We show
that the k-field is driven by an inverse quadratic polynomial potential. The
solutions represent expanding, contracting or bouncing universes with a finite
time span and some of them end in a big crunch or a big rip. Besides, by
selecting the extended tachyonic kinetic functions we analyze the high and low
energy limits of our model, obtaining the nearly power law solution. We
introduce a tachyon field with negative energy density and show that the
universe evolves between two singularities.Comment: 4 pages, jpconf.cls, to appear in Proceedings of Spanish Relativity
Meeting 2009 (ERE 09
The Polarization and the Recombination Mechanism
We use the recombination and the Thomas Precession Model to obtain a
prediction for the polarization in the
reaction. We study the effect of the recombination function on the
polarization.Comment: 4 pages, LaTex, 1 figures included, aipproc.sty included. Talk
presented at Simposio Latino Americano de Fisica de Altas Energias, Merida,
Mexico, November 199
Traumatic Neuroma Following Sagittal Split Osteotomy of the Mandible
A 16-year-old male underwent bilateral sagittal split osteotomy of the mandible to correct a mandibular deficiency. Twenty-one years later, a routine panoramic radiograph revealed a radiolucent lesion on the left side of the mandible. The lesion was biopsied. As the patient did not have symptoms and the lesion was connected to the inferior alveolar nerve, the lesion was not totally excised in order to preserve nerve function. The histological features were consistent with traumatic neuroma, and no further surgical procedure was planned
Two-dimensional scattering and bound states of polar molecules in bilayers
Low-energy two-dimensional scattering is particularly sensitive to the
existence and properties of weakly-bound states. We show that interaction
potentials with vanishing zero-momentum Born approximation lead to an anomalously weak bound state which crucially modifies the
two-dimensional scattering properties. This anomalous case is especially
relevant in the context of polar molecules in bilayer arrangements.Comment: 4 pages, 3 figure
Time evolution of decay of two identical quantum particles
An analytical solution for the time evolution of decay of two identical non
interacting quantum particles seated initially within a potential of finite
range is derived using the formalism of resonant states. It is shown that the
wave function, and hence also the survival and nonescape probabilities, for
factorized symmetric and entangled symmetric/antisymmetric initial states
evolve in a distinctive form along the exponentially decaying and
nonexponential regimes. Our findings show the influence of the Pauli exclusion
principle on decay. We exemplify our results by solving exactly the s-wave
delta shell potential model.Comment: 14 pages, 3 figures, added references and discussio
Tunable beam displacer
We report the implementation of a tunable beam displacer, composed of a
polarizing beam splitter (PBS) and two mirrors, that divides an initially
polarized beam into two parallel beams whose separation can be continuously
tuned. The two output beams are linearly polarized with either vertical or
horizontal polarization and no optical path difference is introduced between
them. The wavelength dependence of the device as well as the maximum separation
between the beams achievable is limited mainly by the PBS characteristics.Comment: 3 pages, 2 figure
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