66,597 research outputs found
A covariantly foliated higher dimensional space-time: Implications for short distance gravity and BSM physics
We consider the space-time at short distances in which it is described by a
-dimensional manifold (bulk) carrying out the principal bundle structure. As
a result, this space-time manifold is foliated in the covariant way by the
-dimensional submanifolds, realized as the space-like internal spaces,
that are smooth copies of the Lie group considered in this paper as the
special unitary group. The submanifolds being transversal to the internal
spaces are realized as the external spaces and in fact identified as the usual
-dimensional world. The fundamental degrees of freedom determining the
geometrical dynamics of the bulk corresponding with short distance gravity are
given by the gauge fields, the external metric field and the modulus fields
setting dynamically the volume of the internal spaces. These gauge fields
laying the bulk is to point precisely out the local directions of the external
spaces which depend on the topological non-triviality of the space-time
principal bundle. The physical size of the internal spaces is fixed dynamically
by the moduli stabilization potential which completely arise from the intrinsic
geometry of the bulk. A detail description of the low energy bulk gravity in
the weak field limit is given around the classical ground state of the bulk.
Additionally, we investigate the dynamics of the fundamentally -dimensional
Weyl spinor fields and the fields of carrying out the non-trivial
representations of the Lie group propagating in the bulk in a detail study.
These results suggest naturally the possible solutions to some the experimental
problems of Standard Model, the smallness of the observed neutrino masses and a
dark matter candidate.Comment: 33 pages, 1 figure. Improved version with some rewriting, title
change
Gauge theory of quantum gravity
The gravity is classically formulated as the geometric curvature of the
space-time in general relativity which is completely different from the other
well-known physical forces. Since seeking a quantum framework for the gravity
is a great challenge in physics. Here we present an alternative construction of
quantum gravity in which the quantum gravitational degrees of freedom are
described by the non-Abelian gauge fields characterizing topological
non-triviality of the space-time. The quantum dynamics of the space-time thus
corresponds to the superposition of the distinct topological states. Its
unitary time evolution is described by the path integral approach. This result
will also be suggested to solve some major problems in physics of the black
holes.Comment: 11 pages, discussions and references added, a mistake of Eq. (10)
corrected, results unchange
Statistics of random lasing modes and amplified spontaneous emission spikes in weakly scattering systems
We have measured the spectral correlations and intensity statistics of random
lasing modes in weakly scattering systems, and compared them to those of the
amplified spontaneous emission spikes. Their dramatic differences revealed the
distinct physical mechanisms. We find that local excitation of a weakly
scattering system may greatly reduce the number of lasing modes even without
absorption outside the pumped region. The lasing modes can be very different
from the quasimodes of the passive system due to selective amplification of the
feedback from the scatterers within the local gain region
Charmonium resonances and Fano line shapes
Anomalous line shapes of quarkonia are explained naturally as an interference
effect of a confined closed channel with the surrounding continua,
well established in other fields of physics as Fano-resonances. We discuss a
quark model coupled-channel analysis describing quarkonium as a mixing of
closed and molecular-like open channels. The asymmetric
line shapes observed in production cross sections in
annihilation to and , respectively, are described very
well. The method allows to extract directly from the data the amount of configuration mixing.Comment: 4 pages, 4 figure
Some new bounds of placement delivery arrays
Coded caching scheme is a technique which reduce the load during peak traffic
times in a wireless network system. Placement delivery array (PDA in short) was
first introduced by Yan et al.. It can be used to design coded caching scheme.
In this paper, we prove some lower bounds of PDA on the element and some lower
bounds of PDA on the column. We also give some constructions for optimal PDA.Comment: Coded caching scheme, placement delivery array, optima
Almost resolvable -cycle systems with
In this paper, we show that if and , then there
exists an almost resolvable -cycle system of order for all
except possibly for and . Thus we give a partial solution to an
open problem posed by Lindner, Meszka, and Rosa (J. Combin. Des., vol. 17,
pp.404-410, 2009).Comment: cycle system; almost resolvable cycle system. arXiv admin note:
substantial text overlap with arXiv:1706.05958, arXiv:1605.0081
Completing the spectrum of almost resolvable cycle systems with odd cycle length
In this paper, we construct almost resolvable cycle systems of order
for odd . This completes the proof of the existence of almost
resolvable cycle systems with odd cycle length.Comment: k-cycle system; almost resolvable cycle system. arXiv admin note:
substantial text overlap with arXiv:1605.0081
The nature and line shapes of charmonium in the reactions
We explore the nature of sharp resonances with asymmetric line shape observed
in cross section data, a general physical phenomenon produced by the
interference of continuum background and resonances. A Fano scheme and the
coupled-channel T-matrix approach are employed to this aim and their close
relationship is present. As a typical example, we point out that the
state observed in the reactions with an anomalous line
shape can be explained naturally as a resonance embedded in the
continuum. From a coupled-channels analysis the background of
resonance is found to originate from a pole at 30.0~MeV.
As a by-product, the broad structure seen in the Belle data,
is found to be the tail of the state, distorted by the opening of
the channel and the onset of the spectral
distribution, thus making the assignment as a genuine charmonium state
unlikely.Comment: 11 pages, 4 figures, extended versio
Wave interference effect on polymer microstadium laser
We investigate the lasing modes in fully chaotic polymer microstadiums under
optical pumping. The lasing modes are regularly spaced in frequency, and their
amplitudes oscillate with frequency. Our numerical simulations reveal that the
lasing modes are multi-orbit scar modes. The interference of partial waves
propagating along the constituent orbits results in local maxima of quality
factor at certain frequencies. The observed modulation of lasing mode amplitude
with frequency results from the variation of quality factor, which provides the
direct evidence of wave interference effect in open chaotic microcavities
About the Calabi problem: a finite dimensional approach
Let us consider a projective manifold and a volume form. We define
the gradient flow associated to the problem of -balanced metrics in the
quantum formalism, the \Omega\Omega\Omega\Omega$-K\"ahler flow and proves its long time existence and convergence
towards the solution to the Calabi problem of prescribing the volume form in a
given K\"ahler class. We derive some natural geometric consequences of our
study.Comment: 38 pages. Revised version with improved expositio
- …