39,579 research outputs found
Adiabatic self-tuning in a silicon microdisk optical resonator
We demonstrate a method for adiabatically self-tuning a silicon microdisk resonator. This mechanism is not only able to sensitively probe the fast nonlinear cavity dynamics, but also provides various optical functionalities like pulse compression, shaping, and tunable time delay
Computing the lower and upper bounds of Laplace eigenvalue problem: by combining conforming and nonconforming finite element methods
This article is devoted to computing the lower and upper bounds of the
Laplace eigenvalue problem. By using the special nonconforming finite elements,
i.e., enriched Crouzeix-Raviart element and extension , we get
the lower bound of the eigenvalue. Additionally, we also use conforming finite
elements to do the postprocessing to get the upper bound of the eigenvalue. The
postprocessing method need only to solve the corresponding source problems and
a small eigenvalue problem if higher order postprocessing method is
implemented. Thus, we can obtain the lower and upper bounds of the eigenvalues
simultaneously by solving eigenvalue problem only once. Some numerical results
are also presented to validate our theoretical analysis.Comment: 19 pages, 4 figure
Top Quark Rare Decays via Loop-Induced FCNC Interactions in Extended Mirror Fermion Model
Flavor changing neutral current (FCNC) interactions for a top quark
decays into with represents a neutral gauge or Higgs boson, and a
up- or charm-quark are highly suppressed in the Standard Model (SM) due to the
Glashow-Iliopoulos-Miami mechanism. Whilst current limits on the branching
ratios of these processes have been established at the order of from
the Large Hadron Collider experiments, SM predictions are at least nine orders
of magnitude below. In this work, we study some of these FCNC processes in the
context of an extended mirror fermion model, originally proposed to implement
the electroweak scale seesaw mechanism for non-sterile right-handed neutrinos.
We show that one can probe the process for a wide range of parameter
space with branching ratios varying from to , comparable
with various new physics models including the general two Higgs doublet model
with or without flavor violations at tree level, minimal supersymmetric
standard model with or without -parity, and extra dimension model.Comment: 30 pages, 8 figures, 2 tables and 1 appendix. Version to appear in
NP
Gamma-Ray Bursts are Produced Predominately in the Early Universe
It is known that some observed gamma-ray bursts (GRBs) are produced at
cosmological distances and that the GRB production rate may follow the star
formation rate. We model the BATSE-detected intensity distribution of long GRBs
in order to determine their space density distribution and opening angle
distribution. Our main results are: the lower and upper distance limits to the
GRB production are z 0.24 and >10, respectively; the GRB opening angle follows
an exponential distribution and the mean opening angle is about 0.03 radians;
and the peak luminosity appears to be a better standard candle than the total
energy of a GRB.Comment: 12 pages, 2 figur
A proposal for highly tunable optical parametric oscillation in silicon micro-resonators
We propose a novel scheme for continuous-wave pumped optical parametric oscillation (OPO) inside silicon micro-resonators. The proposed scheme not only requires a relative low lasing threshold, but also exhibits extremely broad tunability extending from the telecom band to mid infrared
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