6,449 research outputs found

### Supermagnets and Sigma models

We discuss new methods for non-compact sigma models with and without RR
fluxes. The methods include reduction to one dimensional supermagnets,
supercoset constructions and supertwistors. This work is a first step towards
the solution of these models, which are important in several areas of physics.
I dedicate it to the memory of Volodya Gribov.Comment: 22 page

### The wall of the cave

In this article old and new relations between gauge fields and strings are
discussed. We add new arguments that the Yang Mills theories must be described
by the non-critical strings in the five dimensional curved space. The physical
meaning of the fifth dimension is that of the renormalization scale represented
by the Liouville field. We analyze the meaning of the zigzag symmetry and show
that it is likely to be present if there is a minimal supersymmetry on the
world sheet. We also present the new string backgrounds which may be relevant
for the description of the ordinary bosonic Yang-Mills theories. The article is
written on the occasion of the 40-th anniversary of the IHES.Comment: 18 pages, Late

### Gravitating Monopole-Antimonopole Systems at Large Scalar Coupling

We discuss static axially symmetric solutions of SU(2)
Einstein-Yang-Mills-Higgs theory for large scalar coupling. These regular
asymptotically flat solutions represent monopole-antimonopole chain and vortex
ring solutions, as well as new configurations, present only for larger values
of the scalar coupling. When gravity is coupled to the Yang-Mills-Higgs system,
branches of gravitating solutions emerge from the flat-space solutions, and
extend up to critical values of the gravitational coupling constant. For small
scalar coupling only two branches of gravitating solutions exist, where the
second branch connects to a generalized Bartnik-McKinnon solution. For large
scalar coupling, however, a plethora of gravitating branches can be present and
indicate the emergence of new flat-space branches.Comment: 29 pages, 13 figure

### Gauge Fields and Space-Time

In this article I attempt to collect some ideas,opinions and formulae which
may be useful in solving the problem of gauge/ string / space-time
correspondence This includes the validity of D-brane representation, counting
of gauge-invariant words, relations between the null states and the Yang-Mills
equations and the discussion of the strong coupling limit of the string sigma
model. The article is based on the talk given at the "Odyssey 2001" conference.Comment: 20 page

### Electric charge in the field of a magnetic event in three-dimensional spacetime

We analyze the motion of an electric charge in the field of a magnetically
charged event in three-dimensional spacetime. We start by exhibiting a first
integral of the equations of motion in terms of the three conserved components
of the spacetime angular momentum, and then proceed numerically. After crossing
the light cone of the event, an electric charge initially at rest starts
rotating and slowing down. There are two lengths appearing in the problem: (i)
the characteristic length $\frac{q g}{2 \pi m}$, where $q$ and $m$ are the
electric charge and mass of the particle, and $g$ is the magnetic charge of the
event; and (ii) the spacetime impact parameter $r_0$. For $r_0 \gg \frac{q g}{2
\pi m}$, after a time of order $r_0$, the particle makes sharply a quarter of a
turn and comes to rest at the same spatial position at which the event happened
in the past. This jump is the main signature of the presence of the magnetic
event as felt by an electric charge. A derivation of the expression for the
angular momentum that uses Noether's theorem in the magnetic representation is
given in the Appendix.Comment: Version to appear in Phys. Rev.

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