11,598 research outputs found
Isospin particle on with arbitrary number of supersymmetries
We study the supersymmetric quantum mechanics of an isospin particle in the
background of spherically symmetric Yang-Mills gauge field. We show that on
the number of supersymmetries can be made arbitrarily large for a
specific choice of the spherically symmetric SU(2) gauge field. However, the
symmetry algebra containing the supercharges becomes nonlinear if the number of
fermions is greater than two. We present the exact energy spectra and
eigenfunctions, which can be written as the product of monopole harmonics and a
certain isospin state. We also find that the supersymmetry is spontaneously
broken if the number of supersymmetries is even.Comment: 6 page
Magnetic fields in multiple bright-rimmed clouds in different directions of HII region IC1396 - II
Bright-rimmed clouds form on the edges of H II regions affected by the high
energy radiation from a central ionizing source. The UV radiation from the
ionizing source results in compression and ionization causing either cloud
disruption or further star formation. In this work, we present R-band
polarization measurements towards four bright-rimmed clouds, IC1396A, BRC 37,
BRC 38, and BRC 39, located in the different directions of the H II region,
Sh2-131, in order to map magnetic fields (B-fields) in the plane of the sky.
These BRCs are illuminated by the O star HD206267 and present a range of
projected on sky geometries. This provides an opportunity to understand the
magnetized evolution of BRCs. The B-field geometries of the clouds deduced from
the polarization data, after correction for foreground ISM contamination, are
seen to be connected to the ambient B-fields on the large scale. They seem to
play an important role in shaping the cloud IC1396A and BRC 37. BRCs 38 and 39
show a broader and snubber head morphology possibly due to the B-fields being
aligned with incoming radiation as explained in the simulations. A good general
agreement is noted on comparing our observational results with the simulations
supporting the importance of B-fields in BRC evolution. This work is the first
step towards systematic mapping the B-fields morphology in multiple BRCs in an
expanding H II region, extending the work presented by Soam et al. (2017b).Comment: 13 pages, 8 figures, accepted for publication in MNRA
Numerical Analysis of Solid Rocket Motor Instabilities With AP Composite Propellants
A non-steady model for the combustion of ammonium
perchlorate composite propellants has been developed
in order to be incorporated into a comprehensive gasdynamics
model of solid rocket motor flow fields. The
model including the heterogeneous combustion and turbulence
mechanisms is applied to nonlinear combustion
instability analyses. This paper describes the essential
mechanisms and features of the model and discusses the
methodology of non-steady calculations of the combustion
instabilities of solid rocket motors
Hybridization gap and Fano resonance in SmB
We present results of Scanning Tunneling Microscopy and Spectroscopy (STS)
measurements on the "Kondo insulator" SmB. The vast majority of surface
areas investigated was reconstructed but, infrequently, also patches of varying
size of non-reconstructed, Sm- or B-terminated surfaces were found. On the
smallest patches, clear indications for the hybridization gap and
inter-multiplet transitions were observed. On non-reconstructed surface areas
large enough for coherent co-tunneling we were able to observe clear-cut Fano
resonances. Our locally resolved STS indicated considerable finite conductance
on all surfaces independent of their structure.Comment: 5 pages, 4 figure
BRST invariance and de Rham-type cohomology of 't Hooft-Polyakov monopole
We exploit the 't Hooft-Polyakov monopole to define closed algebra of the
quantum field operators and the BRST charge . In the first-class
configuration of the Dirac quantization, by including the -exact
gauge fixing term and the Faddeev-Popov ghost term, we find the BRST invariant
Hamiltonian to investigate the de Rham-type cohomology group structure for the
monopole system. The Bogomol'nyi bound is also discussed in terms of the
first-class topological charge defined on the extended internal 2-sphere.Comment: 8 page
The Solar Proton Burning Process Revisited In Chiral Perturbation Theory
The proton burning process p + p -> d + e(+) + \nu(e), important for the
stellar evolution of main-sequence stars of mass equal to or less than that of
the Sun, is computed in effective field theory using chiral perturbation
expansion to the next-to-next-to leading chiral order. This represents a
model-independent calculation consistent with low-energy effective theory of
QCD comparable in accuracy to the radiative np capture at thermal energy
previously calculated by first using very accurate two-nucleon wavefunctions
backed up by an effective field theory technique with a finite cut-off. The
result obtained thereby is found to support within theoretical uncertainties
the previous calculation of the same process by Bahcall and his co-workers.Comment: 30 pages, 2 eps files, aaspp4.sty needed, slightly modified, to be
published in Ap.
Reply to "Comment on 'Scalar-tensor gravity coupled to a global monopole and flat rotation curves' "
In Brans-Dicke theory of gravity we explain how the extra constant value in
the formula for rotation velocities of stars in a galactic halo can be obtained
due to the global monopole field. We argue on a few points of the preceding
Comment and discuss improvement of our model.Comment: 4 pages, RevTeX4 fil
Time-delayed Spatial Patterns in a Two-dimensional Array of Coupled Oscillators
We investigated the effect of time delays on phase configurations in a set of
two-dimensional coupled phase oscillators. Each oscillator is allowed to
interact with its neighbors located within a finite radius, which serves as a
control parameter in this study. It is found that distance-dependent
time-delays induce various patterns including traveling rolls, square-like and
rhombus-like patterns, spirals, and targets. We analyzed the stability
boundaries of the emerging patterns and briefly pointed out the possible
empirical implications of such time-delayed patterns.Comment: 5 Figure
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