3,068,036 research outputs found
Interaction between two Fuzzy Spheres
We have calculated interactions between two fuzzy spheres in 3 dimension. It
depends on the distance r between the spheres and the radii rho_1, rho_2. There
is no force between the spheres when they are far from each other (long
distance case). We have also studied the interaction for r=0 case. We find that
an attractive force exists between two fuzzy sphere surfaces.Comment: Latex file, 13 page
The Spacetime Life of a Non-BPS D-particle
We investigate the classical geometry generated by a stable non-BPS
D-particle. We consider the boundary state of a stable non-BPS D-particle in
the covariant formalism in the type IIB theory orbifolded by (-1)^{F_L} I_4. We
calculate the scattering amplitude between two D-particles in the non-compact
and compact orbifold and analyse the short and long distance behaviour. At
short distances we find no force at order for any radius, and at the
critical radius we find a BPS-like behaviour up to corrections for long
and short distances. Projecting the boundary state on the massless states of
the orbifold closed string spectrum we obtain the large distance behaviour of
the classical solution describing this non-BPS D-particle in the non-compact
and compact cases. By using the non-BPS D-particle as a probe of the background
geometry of another non-BPS D-particle, we recover the no-force condition at
the critical radius and the behaviour of the probe. Moreover, assuming
that the no-force persists for the complete geometry we derive part of the
classical solution for the non-BPS D-particle.Comment: 36 pages, LaTeX, no figures; amplitude for moving particles and
analysis of short and long distance interactions included, some assumptions
clarified, references adde
Heralded photon amplification for quantum communication
Heralded noiseless amplification based on single-photon sources and linear
optics is ideally suited for long-distance quantum communication tasks based on
discrete variables. We experimentally demonstrate such an amplifier, operating
at telecommunication wavelengths. Coherent amplification is performed with a
gain of G=1.98+/-0.2, for a state with a maximum expected gain G=2. We also
demonstrate that there is no need for a stable phase reference between the
initial signal state and the local auxiliary photons used by the amplifier.
These results highlight the potential of heralded quantum amplifiers for
long-distance quantum communication, and bring device-independent quantum key
distribution one step closer.Comment: 5 pages, 4 figure
The Gould's Belt Distances Survey (GOBELINS). V. Distances and Kinematics of the Perseus molecular cloud
We derive the distance and structure of the Perseus molecular cloud by
combining trigonometric parallaxes from Very Long Baseline Array (VLBA)
observations, taken as part of the GOBELINS survey, and Gaia Data Release 2.
Based on our VLBA astrometry, we obtain a distance of 321+/-10 pc for IC 348.
This is fully consistent with the mean distance of 320+/-26 measured by Gaia.
The VLBA observations toward NGC 1333 are insufficient to claim a successful
distance measurement to this cluster. Gaia parallaxes, on the other hand, yield
a mean distance of 293+/-22 pc. Hence, the distance along the line of sight
between the eastern and western edges of the cloud is ~30 pc, which is
significantly smaller than previously inferred. We use Gaia proper motions and
published radial velocities to derive the spatial velocities of a selected
sample of stars. The average velocity vectors with respect to the LSR are
(u,v,w) = (-6.1+/-1.6, 6.8+/-1.1, -0.9+/-1.2) and (-6.4+/-1.0, 2.1+/-1.4,
-2.4+/-1.0) km/s for IC 348 and NGC 1333, respectively. Finally, our analysis
of the kinematics of the stars has shown that there is no clear evidence of
expansion, contraction, or rotational motions within the clusters.Comment: Accepted for publication in Ap
Kinanthropometric Profile and Physical Performance of Athletic Track Events in Relation to Different Runners
The purpose of this study was to find out kinanthropometric profile of 20 Athletes of Middle distance 800 meters, & Long distance runners 5000 meters of Track Event of age 17 years were assessed for the present study. The data of athletes was collected at Athletics Summer Camp 2015 in Kashmir region. The Athletes having participation of at least two years were selected for the current study. All subjects were assessed for height, weight, girths, diameters, and skin fold thickness. The data was analyzed by applying descriptive statistic i.e., mean, standard deviation & t-test to find out the significant differences of/in middle distance and Long distance runners. The long distance runners had taller than long distance runners for standing height, upper leg length, and lower leg length. The middle distance runners 800 significantly greater in weight, skin fold measurements (p<0.05). In Body Girths and Skeletal Diameters no significant differences were found (p>0.05). It is concluded that in some of the parameters there were significant differences between middle distance & long distance runners Long distance runners athletes showed better kinanthropometric measurement. Keywords: Kinanthropometry, Bodyweight, Height, Circumference Skinfold thickness
Probing a D6 + D0 state with D6-branes: SYM - Supergravity correspondence at subleading level
We probe a non-supersymmetric D6 + D0 state with D6-branes and find agreement
at subleading order between the supergravity and super Yang-Mills description
of the long-distance, low-velocity interaction.Comment: LaTeX, 15 pages, no figure
Strange sea asymmetry in nucleons
We evaluate the medium effects in nucleon which can induce an asymmetry of
the strange sea. The short-distance effects determined by the weak interaction
can give rise to where is the medium-induced mass of strange quark by a few KeV at
most, but the long-distance effects by strong interaction could be sizable.Comment: 4 pages and no figures, Talk presented at the Third
Circum-Pan-Pacific Symposium on "High Energy Spin Physics", Oct. 8-13, 2001,
Beijing, Chin
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