32,075 research outputs found
Hopf maps as static solutions of the complex eikonal equation
We demonstrate that a class of torus-shaped Hopf maps with arbitrary linking
number obeys the static complex eikonal equation. Further, we explore the
geometric structure behind these solutions, explaining thereby the reason for
their existence. As this equation shows up as an integrability condition in
certain non-linear field theories, the existence of such solutions is of some
interest.Comment: 13 pages, slight changes in presentation, one paragraph on the
symmetries of the eikonal equation added. Version accepted for publication in
JM
Dynamical chiral symmetry breaking with Minkowski space integral representations
The fermion propagator is studied in the whole Minkowski space with the help
of the Schwinger-Dyson equations. Various integral representations are employed
to get solutions for the dynamical breaking of chiral symmetry in different
regimes of the coupling constant. In particular, in the case of massive boson,
we extend the singularity structure of the fermion propagator to the two real
pole Ansatz.Comment: 4 pages, 4 figures, published version in PR
Anisotropy of photon production: Initial eccentricity or magnetic field
Recent measurements of the azimuthal anisotropy of direct photons in
heavy-ion collisions at the energies of RHIC show that it is of the same order
as the hadronic one. This finding appears to contradict the expected dominance
of photon production from a quark-gluon plasma at an early stage of a heavy-ion
collision. A possible explanation of the strong azimuthal anisotropy of the
photons, given recently, is based on the presence of a large magnetic field in
the early phase of a collision. In this letter, we propose a method to
experimentally measure the degree to which a magnetic field in heavy-ion
collisions is responsible for the observed anisotropy of photon production. The
experimental test proposed in this letter may potentially change our
understanding of the non-equilibrium stage and possible thermalization in
heavy-ion collisions.Comment: 4 pages, 3 figures; version accepted for publication: discussions
extended, MC calculations adde
Integrable subsystem of Yang--Mills dilaton theory
With the help of the Cho-Faddeev-Niemi-Shabanov decomposition of the SU(2)
Yang-Mills field, we find an integrable subsystem of SU(2) Yang-Mills theory
coupled to the dilaton. Here integrability means the existence of infinitely
many symmetries and infinitely many conserved currents. Further, we construct
infinitely many static solutions of this integrable subsystem. These solutions
can be identified with certain limiting solutions of the full system, which
have been found previously in the context of numerical investigations of the
Yang-Mills dilaton theory. In addition, we derive a Bogomolny bound for the
integrable subsystem and show that our static solutions are, in fact, Bogomolny
solutions. This explains the linear growth of their energies with the
topological charge, which has been observed previously. Finally, we discuss
some generalisations.Comment: 25 pages, LaTex. Version 3: appendix added where the equivalence of
the field equations for the full model and the submodel is demonstrated;
references and some comments adde
- …