9,694 research outputs found
Moduli space volume of vortex and localization
Volume of moduli space of BPS vortices on a compact genus h Riemann surface
Sigma_h is evaluated by means of topological field theory and localization
technique. Vortex in Abelian gauge theory with a single charged scalar field
(ANO vortex) is studied first and is found that the volume of the moduli space
agrees with the previous results obtained more directly by integrating over the
moduli space metric. Next we extend the evaluation to non-Abelian gauge groups
and multi-flavors of scalar fields in the fundamental representation. We find
that the result of localization can be consistently understood in terms of
moduli matrix formalism wherever possible. More details are found in our paper
in Prog.Theor.Phys.126 (2011) 637.Comment: 10 pages, talk at the international conference "quantum theory and
symmetries 7" in prague, august 7-13, 201
Exact Charged 2-Body Motion and the Static Balance Condition in Lineal Gravity
We find an exact solution to the charged 2-body problem in
dimensional lineal gravity which provides the first example of a relativistic
system that generalizes the Majumdar-Papapetrou condition for static balance.Comment: latex,7 pages, 2 figure
Self-replication and splitting of domain patterns in reaction-diffusion systems with fast inhibitor
An asymptotic equation of motion for the pattern interface in the
domain-forming reaction-diffusion systems is derived. The free boundary problem
is reduced to the universal equation of non-local contour dynamics in two
dimensions in the parameter region where a pattern is not far from the points
of the transverse instabilities of its walls. The contour dynamics is studied
numerically for the reaction-diffusion system of the FitzHugh-Nagumo type. It
is shown that in the asymptotic limit the transverse instability of the
localized domains leads to their splitting and formation of the multidomain
pattern rather than fingering and formation of the labyrinthine pattern.Comment: 9 pages (ReVTeX), 5 figures (postscript). To be published in Phys.
Rev.
High resolution imaging of molecular line emission from high redshift QSOs
We present moderate (1'') and high resolution (0.2'') observations of the
CO(2-1) emission at 43 GHz, and radio continuum emission at 1.47 GHz, from the
z=4.7 QSO BRI 1202-0725 and the z=4.4 QSO BRI 1335--0417 using the Very Large
Array. The moderate resolution observations show that in both cases the CO
emission is spatially resolved into two components separated by 1'' for
1335-0417 and 4'' for 1202-0725. The high resolution observations show that
each component has sub-structure on scales of 0.2'' to 0.5'', with intrinsic
brightness temperatures > 20K. The CO ladder from (2-1) up to (7-6) suggests a
high kinetic temperature for the gas (70 K), and a high column density (10^{24}
cm^{-2}). In both sources the continuum-to-line ratio: L_{FIR}/L'_{CO(1-0)} =
335. All these characteristics (brightness temperature, excitation temperature,
column density, and continuum-to-line ratio) are comparable to conditions found
in low redshift, ultra-luminous nuclear starburst galaxies. We find that the CO
emitting regions in 1202-0725 and 1335-0417 must be close to face-on in order
to avoid having the gas mass exceed the gravitational mass, implying perhaps
unreasonably large rotational velocities. While this problem is mitigated by
lowering the CO luminosity-to-H_2 mass conversion factor (X), the required X
values become comparable to, or lower than, the minimum values dictated by
optically thin CO emission. We considered the possibility of magnification by
gravitational lensing in order to reduce the molecular gas masses.Comment: aastex 12 postscript figures. to appear in the Astronomical Journa
Exact Relativistic Two-Body Motion in Lineal Gravity
We consider the N-body problem in (1+1) dimensional lineal gravity. For 2
point masses (N=2) we obtain an exact solution for the relativistic motion. In
the equal mass case we obtain an explicit expression for their proper
separation as a function of their mutual proper time. Our solution gives the
exact Hamiltonian to infinite order in the gravitational coupling constant.Comment: latex, 11 pages, 2 figures, final version to appear in Phys. Rev.
Let
Exact Solution for the Metric and the Motion of Two Bodies in (1+1) Dimensional Gravity
We present the exact solution of two-body motion in (1+1) dimensional dilaton
gravity by solving the constraint equations in the canonical formalism. The
determining equation of the Hamiltonian is derived in a transcendental form and
the Hamiltonian is expressed for the system of two identical particles in terms
of the Lambert function. The function has two real branches which join
smoothly onto each other and the Hamiltonian on the principal branch reduces to
the Newtonian limit for small coupling constant. On the other branch the
Hamiltonian yields a new set of motions which can not be understood as
relativistically correcting the Newtonian motion. The explicit trajectory in
the phase space is illustrated for various values of the energy. The
analysis is extended to the case of unequal masses. The full expression of
metric tensor is given and the consistency between the solution of the metric
and the equations of motion is rigorously proved.Comment: 34 pages, LaTeX, 16 figure
Supersymmetric D-brane Bound States with B-field and Higher Dimensional Instantons on Noncommutative Geometry
We classify supersymmetric D0-Dp bound states with a non-zero B-field by
considering T-dualities of intersecting branes at angles. Especially, we find
that the D0-D8 system with the B-field preserves 1/16, 1/8 and 3/16 of
supercharges if the B-field satisfies the ``(anti-)self-dual'' condition in
dimension eight. The D0-branes in this system are described by eight
dimensional instantons on non-commutative R^8. We also discuss the extended
ADHM construction of the eight-dimensional instantons and its deformation by
the B-field. The modified ADHM equations admit a sort of the `fuzzy sphere'
(embeddings of SU(2)) solution.Comment: 20 pages, LaTeX file, typos corrected and references adde
From Labyrinthine Patterns to Spiral Turbulence
A new mechanism for spiral vortex nucleation in nongradient reaction
diffusion systems is proposed. It involves two key ingredients: An Ising-Bloch
type front bifurcation and an instability of a planar front to transverse
perturbations. Vortex nucleation by this mechanism plays an important role in
inducing a transition from labyrinthine patterns to spiral turbulence. PACS
numbers: 05.45.+b, 82.20.MjComment: 4 pages uuencoded compressed postscrip
Anomalous Spin Dynamics observed by High Frequency ESR in Honeycomb Lattice Antiferromagnet InCu2/3V1/3O3
High-frequency ESR results on the S=1/2 Heisenberg hexagonal antiferromagnet
InCu2/3V1/3O3 are reported. This compound appears to be a rare model substance
for the honeycomb lattice antiferromagnet with very weak interlayer couplings.
The high-temperature magnetic susceptibility can be interpreted by the S=1/2
honeycomb lattice antiferromagnet, and it shows a magnetic-order-like anomaly
at TN=38 K. Although, the resonance field of our high-frequency ESR shows the
typical behavior of the antiferromagnetic resonance, the linewidth of our
high-frequency ESR continues to increase below TN, while it tends to decrease
as the temperature in a conventional three-dimensional antiferromagnet
decreases. In general, a honeycomb lattice antiferromagnet is expected to show
a simple antiferromagnetic order similar to that of a square lattice
antiferromagnet theoretically because both antiferromagnets are bipartite
lattices. However, we suggest that the observed anomalous spin dynamics below
TN is the peculiar feature of the honeycomb lattice antiferromagnet that is not
observed in the square lattice antiferromagnet.Comment: 5 pages, 5 figure
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