117147252
THE STANDARD MODEL WITH HIGGS AS GAUGE FIELD ON FOURTH HOMOTOPY GROUP
Based upon a fundamental principle, the generalized gauge principle, we construct a general model with G(L) x G(R)' x Z(2) gauge symmetry, where Z(2) = pi(4)(G(L)) is the fourth homotopy group of the gauge group G(L), by means of the non-commutative differential geometry and reformulating the standard model with the Higgs field being a gauge field on the fourth homotopy group of their gauge groups. We show that in this approach not only the Higgs held is automatically introduced on an equal footing with ordinary Yang-Mills gauge potentials and there are no extra constraints among the parameters at the tree level but also most importantly the models survive quantum corrections.
119356933
Super-Yangian Y( gl(1|1)) and its oscillator realization
On the basis of graded RTT formalism, the defining relation of the super-Yangian is derived and its oscillator realization is constructed.
123950095
Global Solutions of Einstein–Dirac Equation on the Conformal Space*
The difference between the Riemann and Lorentz spinor manifolds of four dimensions is that the Dirac operator of the former is elliptic and that of the latter is hyperbolic. Moreover the spinor group of the former is a compact group and that of the latter is a noncompact group, which is isomorphic to SL(2,C). Hence the results and their interpretation coming from the two theories would be different. In this short note we study only the Lorentz spinor manifold and, especially, the solutions of Einstein-Dirac equations on the conformal space, which is closely related to the AdS/CFT correspondence.
124820814
R-Matrices for Some Inhomogeneous Quantum Groups*
In this paper, some new generalized inhomogeneous quantum groups corresponding to the homogeneous multiparameter quantum groups are constructed, furthermore, the -matrices for these inhomogeneous quantum groups are found.
124010822
ASSOCIATIVITY OF REPRESENTATIONS AND COCYCLES OF GAUGE GROUPS
It is shown that the consistency of certain representations of group requires a mod Z-cocycle condition which leads to some topological quantization constants in corresponding anomalous algebraic relations, such as anomalous commutators and anomalous Jacobi identities. It should be pointed out that the mod Z-cocycles for gauge groups could be constructed by means of the generalized secondary characteristic classes.
123836451
ANOMALIES OF ARBITRARY GAUGE GROUP AND ITS REDUCTION GROUP, EINSTEIN AND LORENTZ ANOMALIES
Based upon the properties of the characteristic classes and their Chern-Simons secondary characteristic classes, the "Abelian" anomalies in , the Euler-Heisenberg effective actions in , as well as the non-Abelian anomalies in for arbitrary gauge group and its reduction subgroup have been investigated thoroughly and the application to the gravitational anomalies is made. It is shown that the "Abelian" anomalies of such groups are equal to each other, their Eu1er-Heisenberg actions are also closely related to each, other, and their non-Abelian anomalies are also equivalent if their common generating functional can be taken as a counter-term. For the gravitational anomalies we present the common generating functional for both non-Abelian Einstein and Lorentz anomalies in and show the relationship between them.
13234345
The γ-ray binary LS 5039: mass and orbit constraints from MOST observations
The results of a coordinated space-based photometric and ground-based spectroscopic observing campaign on the enigmatic γ -ray binary LS 5039 are reported. 16 d of observations from the MOST satellite have been combined with high-resolution optical echelle spectroscopy from the 2.3-m ANU Telescope in Siding Spring, Australia. These observat ions were used to measure the orbital parameters of the binary and to study the properties of stellar wind from the O primary. We found that any broad-band optical photometric variability at the orbital period is below the 2 mmag level, supporting the scenario that the orbital eccentricity of the system is near the 0.24 ± 0.08 value implied by our spectroscopy, which is lower than values previously obtained by other workers. The low amplitude optical variability also implies the component masses are at the higher end of estimates based on the primary’s O6.5V((f)) spectral type with
18038770
Chandra observations of the globular cluster M 54
We have carried out a Chandra observation of the globular cluster M 54. We detected 7 sources located within the half-mass radius of M 54, at a flux limit of 1.5 x 10 -15 erg s -1 cm -2 in the 0.3-8 keV energy band. The spatial distribution and the colour/spectral properties of the 7 sources suggest that they are likely to be cataclysmic variables or LMXBs in the globular cluster. M 54 shows the largest number of X-ray sources with luminosities greater than 10 32 erg s -1 compared to other globular clusters observed using Chandra and XMM-Newton. We searched for a correlation between the number of sources above this luminosity level with globular cluster parameters. We found evidence that the number of sources peaks at a King concentration parameter c ∼ 1.7-1.9, with globular clusters which are core-collapsed or have low-c values having a smaller number of sources. We speculate on possible reasons for this.
8381735
Accretion in dipole magnetic fields: flow structure and X-ray emission of accreting white dwarfs
Field-channelled accretion flows occur in a variety of astrophysical objects, including T Tauri stars, magnetic cataclysmic variables and X-ray pulsars. We consider a curvilinear coordinate system and derive a general hydrodynamic formulation for accretion onto stellar objects confined by a stellar dipole magnetic field. The hydrodynamic equations are solved to determine the velocity, density and temperature profiles of the flow. We use accreting magnetic white-dwarf stars as an illustrative example of astrophysical applications. Our calculations show that the compressional heating due to the field geometry is as important as radiative cooling and gravity in determining the structure of the post-shock flow in accreting white-dwarf stars. The generalisation of the formulation to accretion flows channelled by higher-order fields and the applications to other astrophysical systems are discussed.
12781236
The lower boundary of the accretion column in magnetic cataclysmic variables
Using a parametrized function for the mass loss at the base of the post-shock region, we have constructed a formulation for magnetically confined accretion flows which avoids singularities, such as the infinity in density, at the base associated with all previous formulations. With the further inclusion of a term allowing for the heat input into the base from the accreting white dwarf, we are also able to obtain the hydrodynamic variables to match the conditions in the stellar atmosphere. (We do not, however, carry out a mutually consistent analysis for the match.) Changes to the emitted X-ray spectra are negligible unless the thickness of mass leakage region at the base approaches or exceeds one per cent of the height of the post-shock region. In this case the predicted spectra from higher-mass white dwarfs will be harder, and fits to X-ray data will predict lower white dwarf masses than previous formulations.
17936082
Structures, oscillations and solitons in large-scale multi-component self-gravitating systems
We investigate the structure of dynamics of large self-gravitating astrophysical systems using a self-interacting two-component model. We consider two cases, galaxy clusters and cosmic walls, for illustrations. In both cases stability analyses are conducted using perturbative expansion. We have found that waves and solitons are easily generated in these systems. Our analysis shows that dark matter can be Jeans unstable in the very inner regions of galaxy clusters if it has a large internal degree of freedom. The dark matter core may collapse under external perturbations. We also discuss dark-matter oscillations in galaxy clusters and how mode growth and decay lead to heating of intracluster medium. Our analysis shows that dark-matter solitons with both positive and negative amplitudes can be excited in cosmic walls. Resonances in soliton interaction could enhance gas condensation. The co-existence of the two types of dark-matter solitons implies that bright filaments can arise in dark voids.