548 research outputs found
A Spinor Model for Quantum Cosmology
The question of the interpretation of Wheeler-DeWitt solutions in the context
of cosmological models is addressed by implementing the Hamiltonian constraint
as a spinor wave equation in minisuperspace. We offer a relative probability
interpretation based on a non-closed vector current in this space and a
prescription for a parametrisation of classical solutions in terms of classical
time. Such a prescription can accommodate classically degenerate metrics
describing manifolds with signature change. The relative probability density,
defined in terms of a Killing vector of the Dewitt metric on minisuperspace,
should permit one to identify classical loci corresponding to geometries for a
classical manifold. This interpretation is illustrated in the context of a
quantum cosmology model for two-dimensional dilaton gravity.Comment: 17p, Lanc-Th-G940
End to End Deep Neural Network Frequency Demodulation of Speech Signals
Frequency modulation (FM) is a form of radio broadcasting which is widely
used nowadays and has been for almost a century. We suggest a
software-defined-radio (SDR) receiver for FM demodulation that adopts an
end-to-end learning based approach and utilizes the prior information of
transmitted speech message in the demodulation process. The receiver detects
and enhances speech from the in-phase and quadrature components of its base
band version. The new system yields high performance detection for both
acoustical disturbances, and communication channel noise and is foreseen to
out-perform the established methods for low signal to noise ratio (SNR)
conditions in both mean square error and in perceptual evaluation of speech
quality score
Quaternionic Salkowski Curves and Quaternionic Similar Curves
In this paper, we give the definitions and characterizations of quaternionic
Salkowski, quaternionic anti-Salkowski and quaternionic similar curves in the
Euclidean spaces E^3 and E^4. We obtain relationships between these curves and
some special quaternionic curves such as quaternionic slant helices and
quaternionic B2-slant helices.Comment: 17 page
Lonely Dreamers in Dostoevsky's White Nights and Sabahattin Ali's Madonna in a Fur Coat: A Comparative Analysis
Loneliness is a universal phenomenon that individuals experience at some point their lives regardless of their culture. Hence, the concept of loneliness has been repeatedly discussed and analyzed not only by philosophers, sociologists, psychologists, but also by a great number of writers all through history because of its pervasive role in our individual and social lives. While loneliness as a theme, in general, is employed along with the idea of alienation, in Russian literature, it seems to be related to the term of 'superuous man.' The ideas of dream and love, likewise, have been reected in many works of art and literature. In this light, this paper, within a comparative framework, analyzes two outstanding works - Fyodor Dostoevsky's White Nights (1848) and Sabahattin Ali's Madonna in a Fur Coat (1943) - in terms of their main characters' superuous tendencies diversied by the themes of loneliness, dream, and love
Post-Ottoman Empire European Imaginations of the Image of the Women of Maghreb
This study, as a critical examination, unravels how the non-Western woman has been both reconstructed and represented from a Western male perspective. The representation of Harem and the idea of the ideal Oriental woman in Harem have been analysed repeatedly in scholarly circles. However, this study analyses primarily how the women of Maghreb, of countries such as Tunisia, Algeria, and Morocco, but also Egypt, were represented by the Western male gaze after these places -- once the provinces of the Ottoman Empire -- went under the control of European powers, notably France. Different sources, such as travelogues and paintings, including postcards and drawings from the West – from Germany, France, Austria, and Britain -- have been analysed with a particular emphasis on the women of the Ottoman Orient. Through the analysis of such sources, an outline of a Western representational practice of the non-Western women in general and the women of the Ottoman Orient in particular has been revealed around the idea of the construction of 'the other' and 'the other's identity', thereby mentally programming a justied understanding of that re-constructed identity of the other
On Signature Transition and Compactification in Kaluza-Klein Cosmology
We consider an empty (4+1) dimensional Kaluza-Klein universe with a negative
cosmological constant and a Robertson-Walker type metric. It is shown that the
solutions to Einstein field equations have degenerate metric and exhibit
transitioins from a Euclidean to a Lorentzian domain. We then suggest a
mechanism, based on signature transition which leads to compactification of the
internal space in the Lorentzian region as . With the
assumption of a very small value for the cosmological constant we find that the
size of the universe and the internal scale factor would be related
according to in the Lorentzian region. The corresponding
Wheeler-DeWitt equation has exact solution in the mini-superspace giving rise
to a quantum state which peaks in the vicinity of the classical solutions
undergoing signature transition.Comment: 13 pages, 3 figure
Killing-Yano Forms of a Class of Spherically Symmetric Space-Times II: A Unified Generation of Higher Forms
Killing-Yano (KY) two and three forms of a class of spherically symmetric
space-times that includes the well-known Minkowski, Schwarzschild,
Reissner-Nordstrom, Robertson-Walker and six different forms of de Sitter
space-times as special cases are derived in a unified and exhaustive manner. It
is directly proved that while the Schwarzschild and Reissner-Nordstrom
space-times do not accept any KY 3-form and they accept only one 2-form, the
Robertson-Walker space-time admits four KY 2-forms and only one KY 3-form.
Maximal number of KY-forms are obtained for Minkowski and all known forms of de
Sitter space-times. Complete lists comprising explicit expressions of KY-forms
are given.Comment: 28 page
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