1,101 research outputs found
Cosmological model with local symmetry of very special relativity and constraints on it from supernovae
Based on Cohen \& Glashow's very special relativity [A. G. Cohen and S. L.
Glashow, Phys. Rev. Lett. {\bf 97} (2006) 021601], we propose an anisotropic
modification to the Friedmann-Robertson-Walker (FRW) line element. An
arbitrarily oriented 1-form is introduced and the FRW spacetime becomes of the
Randers-Finsler type. The 1-form picks out a privileged axis in the universe.
Thus, the cosmological redshift as well as the Hubble diagram of the type Ia
supernovae (SNe Ia) becomes anisotropic. By directly analyzing the Union2
compilation, we obtain the privileged axis pointing to
(). This privileged axis is close to those obtained by
comparing the best-fit Hubble diagrams in pairs of hemispheres. It should be
noticed that the result is consistent with isotropy at the level
since the anisotropic magnitude is .Comment: 13 pages, 2 figures. Published at EPJC(2013
Characterization of a RS-LiDAR for 3D Perception
High precision 3D LiDARs are still expensive and hard to acquire. This paper
presents the characteristics of RS-LiDAR, a model of low-cost LiDAR with
sufficient supplies, in comparison with VLP-16. The paper also provides a set
of evaluations to analyze the characterizations and performances of LiDARs
sensors. This work analyzes multiple properties, such as drift effects,
distance effects, color effects and sensor orientation effects, in the context
of 3D perception. By comparing with Velodyne LiDAR, we found RS-LiDAR as a
cheaper and acquirable substitute of VLP-16 with similar efficiency.Comment: For ICRA201
Finslerian MOND versus the Strong Gravitational Lensing of the Early-type Galaxies
The gravitational lensing of Bullet Clusters and early-type galaxies pose
serious challenges on the validity of MOND. Recently, Finslerian MOND, a
generalization of MOND in the framework of Finsler gravity, has been proposed
to explain the mass discrepancy problem of Bullet Cluster 1E 0657\ 558. In this
paper, we check the validity of the Finslerian MOND in describing the strong
gravitational lensing of early-type galaxies. The investigation on ten strong
lenses of the CASTLES samples shows that there is no strong evidence for the
existence of dark matter.Comment: 11 pages, 2 figures, 2 table
Ballistic Thermal Rectification in Asymmetric Three-Terminal Mesoscopic Dielectric Systems
By coupling the asymmetric three-terminal mesoscopic dielectric system with a
temperature probe, at low temperature, the ballistic heat flux flow through the
other two asymmetric terminals in the nonlinear response regime is studied
based on the Landauer formulation of transport theory. The thermal
rectification is attained at the quantum regime. It is a purely quantum effect
and is determined by the dependence of the ratio
on , the phonon's frequency.
Where and are respectively the
transmission coefficients from two asymmetric terminals to the temperature
probe, which are determined by the inelastic scattering of ballistic phonons in
the temperature probe. Our results are confirmed by extensive numerical
simulations.Comment: 10 pages, 4 figure
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