20,373 research outputs found
Effective String Theory of Vortices and Regge Trajectories
Starting from a field theory containing classical vortex solutions, we obtain
an effective string theory of these vortices as a path integral over the two
transverse degrees of freedom of the string. We carry out a semiclassical
expansion of this effective theory, and use it to obtain corrections to Regge
trajectories due to string fluctuations.Comment: 27 pages, revtex, 3 figures, corrected an error with the cutoff in
appendix E (was previously D), added more discussion of Fig. 3, moved some
material in section 9 to a new appendi
On the Dynamical Ferromagnetic, Quantum Hall, and Relativistic Effects on the Carbon Nanotubes Nucleation and Growth Mechanism
The mechanism of carbon nanotube (CNT) nucleation and growth has been a
mystery for over 15 years. Prior models have attempted the extension of older
classical transport mechanisms. In July 2000, a more detailed and accurate
nonclassical, relativistic mechanism was formulated considering the detailed
dynamics of the electronics of spin and orbital rehybridization between the
carbon and catalyst via novel mesoscopic phenomena and quantum dynamics.
Ferromagnetic carbon was demonstrated. Here, quantum (Hall) effects and
relativistic effects of intense many body spin-orbital interactions for novel
orbital rehybridization dynamics (Little Effect) are proposed in this new
dynamical magnetic mechanism. This dynamic ferromagnetic mechanism is proven by
imposing dynamic and static magnetic fields during CNT syntheses and observing
the different influence of these external magnetic environments on the
catalyzing spin currents and spin waves and the resulting CNT formation
Three-neutron resonance trajectories for realistic interaction models
Three-neutron resonances are investigated using realistic nucleon-nucleon
interaction models. The resonance pole trajectories are explored by first
adding an additional interaction to artificially bind the three-neutron system
and then gradually removing it. The pole positions for the three-neutron states
up to J=5/2 are localized in the third energy quadrant-Im (E)<=0, Re
(E)<=0-well before the additional interaction is removed. Our study shows that
realistic nucleon-nucleon interaction models exclude any possible experimental
signature of three-neutron resonances.Comment: 13 pages ; 8 figs ; 5 table
Improved Quantum Hard-Sphere Ground-State Equations of State
The London ground-state energy formula as a function of number density for a
system of identical boson hard spheres, corrected for the reduced mass of a
pair of particles in a sphere-of-influence picture, and generalized to fermion
hard-sphere systems with two and four intrinsic degrees of freedom, has a
double-pole at the ultimate \textit{regular} (or periodic, e.g.,
face-centered-cubic) close-packing density usually associated with a
crystalline branch. Improved fluid branches are contructed based upon exact,
field-theoretic perturbation-theory low-density expansions for many-boson and
many-fermion systems, appropriately extrapolated to intermediate densities, but
whose ultimate density is irregular or \textit{random} closest close-packing as
suggested in studies of a classical system of hard spheres. Results show
substantially improved agreement with the best available Green-function Monte
Carlo and diffusion Monte Carlo simulations for bosons, as well as with ladder,
variational Fermi hypernetted chain, and so-called L-expansion data for
two-component fermions.Comment: 15 pages and 7 figure
Chiral Quasicrystalline Order and Dodecahedral Geometry in Exceptional Families of Viruses
On the example of exceptional families of viruses we i) show the existence of
a completely new type of matter organization in nanoparticles, in which the
regions with a chiral pentagonal quasicrystalline order of protein positions
are arranged in a structure commensurate with the spherical topology and
dodecahedral geometry, ii) generalize the classical theory of quasicrystals
(QCs) to explain this organization, and iii) establish the relation between
local chiral QC order and nonzero curvature of the dodecahedral capsid faces.Comment: 8 pages, 3 figure
Searching for Gravitational Waves with a Geostationary Interferometer
We analyze the sensitivities of a geostationary gravitational wave
interferometer mission operating in the sub-Hertz band. Because of its smaller
armlength, in the lower part of its accessible frequency band ( Hz) our proposed Earth-orbiting detector will be less
sensitive, by a factor of about seventy, than the Laser Interferometer Space
Antenna (LISA) mission. In the higher part of its band instead ( Hz), our proposed interferometer will have the capability of
observing super-massive black holes (SMBHs) with masses smaller than M. With good event rates for these systems, a geostationary
interferometer will be able to accurately probe the astrophysical scenarios
that account for their formation.Comment: 33 pages, 9 eps figure
3D Lya radiation transfer. II. Fitting the Lyman break galaxy MS 1512-cB58 and implications for Lya emission in high-z starbursts
Using our 3D Lya radiation transfer code, we compute the radiation transfer
of Lya and UV continuum photons including dust. Observational constraints on
the neutral gas (column density, kinematics, etc.) are taken from other
analysis of this object. RESULTS: The observed Lya profile of MS 1512--cB58 is
reproduced for the first time taking radiation transfer and all observational
constraints into account. The observed absorption profile is found to result
naturally from the observed amount of dust and the relatively high HI column
density. Radiation transfer effects and suppresion by dust transform a strong
intrinsic Lya emission with EW(Lya)>~ 60 Ang into the observed faint superposed
Lya emission peak. We propose that the vast majority of LBGs have intrinsically
EW(Lya)~60-80 Ang or larger, and that the main physical parameter responsible
for the observed variety of Lya strengths and profiles in LBGs is N_H and the
accompanying variation of the dust content. Observed EW(Lya) distributions, Lya
luminosity functions, and related quantities must therefore be corrected for
radiation transfer and dust effects. The implications from our scenario on the
duty-cycle of Lya emitters are also discussed.Comment: Accepted for publication in A&
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