Zobrazeno 1 - 10
of 30
pro vyhledávání: '"Mielke, E. W."'
Publikováno v:
Mon.Not.Roy.Astron.Soc.369:485-491,2006
A non-topological soliton model with a repulsive scalar self-interaction of the Emden type provides a constant density core,similarly as the empirical Burkert profile of dark matter haloes. As a further test, we derive the gravitational lens properti
Externí odkaz:
http://arxiv.org/abs/astro-ph/0603309
Autor:
Fuchs, B., Mielke, E. W.
Publikováno v:
Mon.Not.Roy.Astron.Soc.350:707,2004
Galactic dark matter is modelled by a scalar field. In particular, it is shown that an analytically solvable toy model with a non-linear self-interaction potential U(Phi) leads to dark halo models which have the form of quasi-isothermal spheres. We a
Externí odkaz:
http://arxiv.org/abs/astro-ph/0401575
Autor:
Tresguerres, R., Mielke, E. W.
Publikováno v:
Phys.Rev. D62 (2000) 044004
In order to facilitate the application of standard renormalization techniques, gravitation should be decribed, if possible, in pure connection formalism, as a Yang-Mills theory of a certain spacetime group, say the Poincare or the affine group. This
Externí odkaz:
http://arxiv.org/abs/gr-qc/0007072
We consider a classical Dirac field in flat Minkowski spacetime. We perform a Gordon decomposition of its canonical energy-momentum and spin currents, respectively. Thereby we find for each of these currents a convective and a polarization piece. The
Externí odkaz:
http://arxiv.org/abs/gr-qc/9706009
Autor:
Mielke, E. W., Kreimer, D.
Publikováno v:
Gen.Rel.Grav.31:701-712,1999
The Dirac equation in Riemann-Cartan spacetimes with torsion is reconsidered. As is well-known, only the axial covector torsion $A$, a one-form, couples to massive Dirac fields. Using diagrammatic techniques, we show that besides the familiar Riemann
Externí odkaz:
http://arxiv.org/abs/gr-qc/9704051
Publikováno v:
Phys.Lett. A192 (1994) 153-162
Recently, the {\it spacelike} part of the $SU(2)$ Yang--Mills equations has been identified with geometrical objects of a three--dimensional space of constant Riemann--Cartan curvature. We give a concise derivation of this Ashtekar type (``inverse Ka
Externí odkaz:
http://arxiv.org/abs/gr-qc/9407031
Publikováno v:
Phys.Rept.258:1-171,1995
In Einstein's gravitational theory, the spacetime is Riemannian, that is, it has vanishing torsion and vanishing nonmetricity (covariant derivative of the metric). In the gauging of the general affine group ${A}(4,R)$ and of its subgroup ${GL}(4,R)$
Externí odkaz:
http://arxiv.org/abs/gr-qc/9402012
Publikováno v:
Phys.Rev. D48 (1993) 3648-3662
It is shown that gravity on the line can be described by the two dimensional (2D) Hilbert-Einstein Lagrangian supplemented by a kinetic term for the coframe and a translational {\it boundary} term. The resulting model is equivalent to a Yang-Mills th
Externí odkaz:
http://arxiv.org/abs/hep-th/9304043
Publikováno v:
Phys.Rev.D48:673-679,1993
In quantum models of gravity, it is surmized that configurations with degenerate coframes could occur during topology change of the underlying spacetime structure. However, the coframe is not the true Yang--Mills type gauge field of the translations,
Externí odkaz:
http://arxiv.org/abs/gr-qc/9301023
