1,476 research outputs found
Derived equivalences between matrix subrings and their applications
In this paper, we construct derived equivalences between matrix subrings. As
applications, we calculate the global dimensions and the finitistic dimensions
of some matrix subrings. And we show that the finitistic dimension conjecture
holds for a class of Harada algebras and a class of tiled triangular algebras.Comment: 16 page
Assessing the effect of lens mass model in cosmological application with updated galaxy-scale strong gravitational lensing sample
By comparing the dynamical and lensing masses of early-type lens galaxies,
one can constrain both the cosmological parameters and the density profiles of
galaxies. We explore the constraining power on cosmological parameters and the
effect of the lens mass model in this method with 161 galaxy-scale strong
lensing systems, which is currently the largest sample with both high
resolution imaging and stellar dynamical data. We assume a power-law mass model
for the lenses, and consider three different parameterizations for
(i.e., the slope of the total mass density profile) to include the effect of
the dependence of on redshift and surface mass density. When treating
(i.e., the slope of the luminosity density profile) as a universal
parameter for all lens galaxies, we find the limits on the cosmological
parameter are quite weak and biased, and also heavily dependent on
the lens mass model in the scenarios of parameterizing with three
different forms. When treating as an observable for each lens, the
unbiased estimate of can be obtained only in the scenario of
including the dependence of on both the redshift and the surface mass
density, that is at 68\% confidence level
in the framework of a flat CDM model. We conclude that the significant
dependencies of on both the redshift and the surface mass density, as
well as the intrinsic scatter of among the lenses, need to be properly
taken into account in this method.Comment: Accepted for publication in MNRAS; 17 pages, 5 figures, 2 table
Revision on palaearctic species of Periclistus Förster with description of a new species and its host plant gall (Hymenoptera, Cynipidae)
Palaearctic species of Periclistus Förster has been systematically described, but a new inquiline gall-wasp, Periclistus qinghainensis sp. n., is described from China. This species was obtained from an unknown stem gall induced on Rosa sp. Diagnosis, distribution and biology of the new species are described in this paper. After examining the types of P. idoneus Belizin, 1973 and P. capillatus Belizin, 1968, it is concluded that P. idoneus belongs to genus Aulacidea, and P. capillatus is a valid species of Periclistus. A key to the Palaearctic Periclistus species is also given
Universal behavior of optimal paths in weighted networks with general disorder
We study the statistics of the optimal path in both random and scale free
networks, where weights are taken from a general distribution . We
find that different types of disorder lead to the same universal behavior.
Specifically, we find that a single parameter ( for
-dimensional lattices, and for random networks)
determines the distributions of the optimal path length, including both strong
and weak disorder regimes. Here is the percolation connectivity exponent,
and depends on the percolation threshold and . For uniform,
Poisson or Gaussian the crossover from weak to strong does not occur, and only
weak disorder exists.Comment: Accepted by PR
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