7,185 research outputs found
Quantum Interference Effects in Spacetime of Slowly Rotating Compact Objects in Braneworld
The phase shift a neutron interferometer caused by the gravitational field
and the rotation of the earth is derived in a unified way from the standpoint
of general relativity. General relativistic quantum interference effects in the
slowly rotating braneworld as the Sagnac effect and phase shift effect of
interfering particle in neutron interferometer are considered. It was found
that in the case of the Sagnac effect the influence of brane parameter is
becoming important due to the fact that the angular velocity of the locally non
rotating observer must be larger than one in the Kerr space-time. In the case
of neutron interferometry it is found that due to the presence of the parameter
an additional term in the phase shift of interfering particle emerges
from the results of the recent experiments we have obtained upper limit for the
tidal charge as . Finally, as an example, we
apply the obtained results to the calculation of the (ultra-cold neutrons)
energy level modification in the braneworld.Comment: 12 pages, 2 figure
The Extragalactic Distance Database: Color-Magnitude Diagrams
The CMDs/TRGB (Color-Magnitude Diagrams/Tip of the Red Giant Branch) section
of the Extragalactic Distance Database contains a compilation of observations
of nearby galaxies from the Hubble Space Telescope. Approximately 250 (and
increasing) galaxies in the Local Volume have CMDs and the stellar photometry
tables used to produce them available through the web. Various stellar
populations that make up a galaxy are visible in the CMDs, but our primary
purpose for collecting and analyzing these galaxy images is to measure the TRGB
in each. We can estimate the distance to a galaxy by using stars at the TRGB as
standard candles. In this paper we describe the process of constructing the
CMDs and make the results available to the public.Comment: 8 pages, 5 figures, 1 long table, submitted to Astronomical Journa
Faster FPTASes for counting and random generation of Knapsack solutions
In the #P-complete problem of counting 0/1 Knapsack solutions, the input consists of a sequence of n nonnegative integer weights w1,…,wn and an integer C, and we have to find the number of subsequences (subsets of indices) with total weight at most C. We give faster and simpler fully polynomial-time approximation schemes (FPTASes) for this problem, and for its random generation counterpart. Our method is based on dynamic programming and discretization of large numbers through floating-point arithmetic. We improve both deterministic counting FPTASes from Gopalan et al. (2011) [9], Štefankovič et al. (2012) [6] and the randomized counting and random generation algorithms in Dyer (2003) [5]. Our method is general, and it can be directly applied on top of combinatorial decompositions (such as dynamic programming solutions) of various problems. For example, we also improve the complexity of the problem of counting 0/1 Knapsack solutions in an arc-weighted DAG.Peer reviewe
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