6,259 research outputs found
Quantum Cloning, Bell's Inequality and Teleportation
We analyze a possibility of using the two qubit output state from
Buzek-Hillery quantum copying machine (not necessarily universal quantum
cloning machine) as a teleportation channel. We show that there is a range of
values of the machine parameter for which the two qubit output state is
entangled and violates Bell-CHSH inequality and for a different range it
remains entangled but does not violate Bell-CHSH inequality. Further we observe
that for certain values of the machine parameter the two-qubit mixed state can
be used as a teleportation channel. The use of the output state from the
Buzek-Hillery cloning machine as a teleportation channel provides an additional
appeal to the cloning machine and motivation of our present work.Comment: 7 pages and no figures, Accepted in Journal of Physics
On Deterministic Sketching and Streaming for Sparse Recovery and Norm Estimation
We study classic streaming and sparse recovery problems using deterministic
linear sketches, including l1/l1 and linf/l1 sparse recovery problems (the
latter also being known as l1-heavy hitters), norm estimation, and approximate
inner product. We focus on devising a fixed matrix A in R^{m x n} and a
deterministic recovery/estimation procedure which work for all possible input
vectors simultaneously. Our results improve upon existing work, the following
being our main contributions:
* A proof that linf/l1 sparse recovery and inner product estimation are
equivalent, and that incoherent matrices can be used to solve both problems.
Our upper bound for the number of measurements is m=O(eps^{-2}*min{log n, (log
n / log(1/eps))^2}). We can also obtain fast sketching and recovery algorithms
by making use of the Fast Johnson-Lindenstrauss transform. Both our running
times and number of measurements improve upon previous work. We can also obtain
better error guarantees than previous work in terms of a smaller tail of the
input vector.
* A new lower bound for the number of linear measurements required to solve
l1/l1 sparse recovery. We show Omega(k/eps^2 + klog(n/k)/eps) measurements are
required to recover an x' with |x - x'|_1 <= (1+eps)|x_{tail(k)}|_1, where
x_{tail(k)} is x projected onto all but its largest k coordinates in magnitude.
* A tight bound of m = Theta(eps^{-2}log(eps^2 n)) on the number of
measurements required to solve deterministic norm estimation, i.e., to recover
|x|_2 +/- eps|x|_1.
For all the problems we study, tight bounds are already known for the
randomized complexity from previous work, except in the case of l1/l1 sparse
recovery, where a nearly tight bound is known. Our work thus aims to study the
deterministic complexities of these problems
Soliton Lattice and Single Soliton Solutions of the Associated Lam\'e and Lam\'e Potentials
We obtain the exact nontopological soliton lattice solutions of the
Associated Lam\'e equation in different parameter regimes and compute the
corresponding energy for each of these solutions. We show that in specific
limits these solutions give rise to nontopological (pulse-like) single
solitons, as well as to different types of topological (kink-like) single
soliton solutions of the Associated Lam\'e equation. Following Manton, we also
compute, as an illustration, the asymptotic interaction energy between these
soliton solutions in one particular case. Finally, in specific limits, we
deduce the soliton lattices, as well as the topological single soliton
solutions of the Lam\'e equation, and also the sine-Gordon soliton solution.Comment: 23 pages, 5 figures. Submitted to J. Math. Phy
Emergence of a non-scaling degree distribution in bipartite networks: a numerical and analytical study
We study the growth of bipartite networks in which the number of nodes in one
of the partitions is kept fixed while the other partition is allowed to grow.
We study random and preferential attachment as well as combination of both. We
derive the exact analytical expression for the degree-distribution of all these
different types of attachments while assuming that edges are incorporated
sequentially, i.e., a single edge is added to the growing network in a time
step. We also provide an approximate expression for the case when more than one
edge are added in a time step. We show that depending on the relative weight
between random and preferential attachment, the degree-distribution of this
type of network falls into one of four possible regimes which range from a
binomial distribution for pure random attachment to an u-shaped distribution
for dominant preferential attachment
Learning Engagement of Adult Females in Remote Physical Fitness Program Through Mobile App Intervention
The use of digital devices such as laptops, personal digital assistants, and mobile phones as learning tools has gained prominence in formal education, generating increased research interest in potential growth areas. According to Jeong and So (2020), there seems to be inadequate empirical evidence from extensive research to support its learning effectiveness in the fitness domain, especially among women who have been underrepresented in economically stressed areas. One of the several explanations for this disparity is the failure to consider women’s intersecting cultural identities or potential for social impact. This paper focuses on addressing this issue by conducting a qualitative study. It involves a focus group comprising 15 adult females aged 24 and above. The primary objective is to assess how virtual learning influences the learning perception of adult female learners at a yoga and fitness studio. Interactive self-paced mobile-assisted learning modules were facilitated through the use of mobile phones. An open-ended questionnaire was designed using online resources for primary data collection. The findings were derived by cross-referencing data collected from recordings, interviews, and questionnaires. The study revealed that participating in online fitness classes could enhance women's involvement in fitness-related activities
Learning Engagement of Adult Females in Remote Physical Fitness Program Through Mobile App Intervention
The use of digital devices such as laptops, personal digital assistants, and mobile phones as learning tools has gained prominence in formal education, generating increased research interest in potential growth areas. According to Jeong and So (2020), there seems to be inadequate empirical evidence from extensive research to support its learning effectiveness in the fitness domain, especially among women who have been underrepresented in economically stressed areas. One of the several explanations for this disparity is the failure to consider women’s intersecting cultural identities or potential for social impact. This paper focuses on addressing this issue by conducting a qualitative study. It involves a focus group comprising 15 adult females aged 24 and above. The primary objective is to assess how virtual learning influences the learning perception of adult female learners at a yoga and fitness studio. Interactive self-paced mobile-assisted learning modules were facilitated through the use of mobile phones. An open-ended questionnaire was designed using online resources for primary data collection. The findings were derived by cross-referencing data collected from recordings, interviews, and questionnaires. The study revealed that participating in online fitness classes could enhance women's involvement in fitness-related activities
An HST/COS legacy survey of high-velocity ultraviolet absorption in the Milky Way's circumgalactic medium and the Local Group
To characterize the absorption properties of this circumgalactic medium (CGM)
and its relation to the LG we present the so-far largest survey of metal
absorption in Galactic high-velocity clouds (HVCs) using archival ultraviolet
(UV) spectra of extragalactic background sources. The UV data are obtained with
the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST)
and are supplemented by 21 cm radio observations of neutral hydrogen. Along 270
sightlines we measure metal absorption in the lines of SiII, SiIII, CII, and
CIV and associated HI 21 cm emission in HVCs in the velocity range
|v_LSR|=100-500 km s^-1. With this unprecedented large HVC sample we were able
to improve the statistics on HVC covering fractions, ionization conditions,
small-scale structure, CGM mass, and inflow rate. For the first time, we
determine robustly the angular two point correlation function of the
high-velocity absorbers, systematically analyze antipodal sightlines on the
celestial sphere, and compare the absorption characteristics with that of
Damped Lyman alpha absorbers (DLAs) and constrained cosmological simulations of
the LG. Our study demonstrates that the Milky Way CGM contains sufficient
gaseous material to maintain the Galactic star-formation rate at its current
level. We show that the CGM is composed of discrete gaseous structures that
exhibit a large-scale kinematics together with small-scale variations in
physical conditions. The Magellanic Stream clearly dominates both the cross
section and mass flow of high-velocity gas in the Milky Way's CGM. The possible
presence of high-velocity LG gas underlines the important role of the local
cosmological environment in the large-scale gas-circulation processes in and
around the Milky Way (abridged).Comment: 37 pages, 25 figures, 8 tables, accepted for publication in A&
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