32,795 research outputs found

### Bosonic vacuum wave functions from the BCS-type wave function of the ground state of the massless Thirring model

A BCS-type wave function describes the ground state of the massless Thirring
model in the chirally broken phase. The massless Thirring model with fermion
fields quantized in the chirally broken phase bosonizes to the quantum field
theory of the free massless (pseudo)scalar field (Eur. Phys. J. C20, 723
(2001)). The wave functions of the ground state of the free massless
(pseudo)scalar field are obtained from the BCS-type wave function by averaging
over quantum fluctuations of the Thirring fermion fields. We show that these
wave functions are orthogonal, normalized and non-invariant under shifts of the
massless (pseudo)scalar field. This testifies the spontaneous breaking of the
field-shift symmetry in the quantum field theory of a free massless
(pseudo)scalar field. We show that the vacuum-to-vacuum transition amplitude
calculated for the bosonized BCS-type wave functions coincides with the
generating functional of Green functions defined only by the contribution of
vibrational modes (Eur. Phys. J. C 24, 653 (2002)) . This confirms the
assumption that the bosonized BCS-type wave function is defined by the
collective zero-mode (hep-th/0212226). We argue that the obtained result is not
a counterexample to the Mermin-Wagner-Hohenberg and Coleman theorems.Comment: 9 pages, Latex, no figures, Revised according to the version accepted
for publication in Physics Letters

### Towards the Deconfinement Phase Transition in Hot Gauge Theories

The phase structure of hot gauge theories with dynamical matter fields is
reexamined in the canonical ensemble with respect to triality. We discuss
properties of chromoelectric and chromomagnetic sectors of the theory and show
whereas electric charges carrying a unit of Z(N) charge are screened at high
temperatures via dynamical matter loops, this is not the case for the Z(N)
magnetic flux. An order parameter is constructed to probe the realization of
local Z(N) symmetry in the magnetic sector. We argue this order parameter may
be used to detect the deconfinement phase transition which is defined in terms
of the screening mechanism.Comment: poster presented at LATTICE97; 3 pages, late

### Center Vortices at Strong Couplings

A long-range effective action is derived for strong-coupling lattice SU(2)
gauge theory in D=3 dimensions. It is shown that center vortices emerge as
stable saddlepoints of this action.Comment: Lattice 2000 (Topology and Vacuum), 4 page

### On the Wilson loop in the dual representation within the dual Higgs model with dual Dirac strings

The vacuum expectation value of the Wilson loop in the dual representation is
calculated in the dual Higgs model with dual Dirac strings. It is shown that
the averaged value of the Wilson loop in the dual representation obeys the
area-law falloff. Quantum fluctuations of the dual-vector and the Higgs field
around Abrikosov flux lines induced by dual Dirac strings in a dual
superconducting vacuum and string shape fluctuations are taken into account.Comment: 9 pages, latex, no figure

### Virasoro constraints and the Chern classes of the Hodge bundle

We analyse the consequences of the Virasoro conjecture of Eguchi, Hori and
Xiong for Gromov-Witten invariants, in the case of zero degree maps to the
manifolds CP^1 and CP^2 (or more generally, smooth projective curves and smooth
simply-connected projective surfaces). We obtain predictions involving
intersections of psi and lambda classes on the compactification of M_{g,n}. In
particular, we show that the Virasoro conjecture for CP^2 implies the numerical
part of Faber's conjecture on the tautological Chow ring of M_g.Comment: 12 pages, latex2

### Towards transversality of singular varieties: splayed divisors

We study a natural generalization of transversally intersecting smooth
hypersurfaces in a complex manifold: hypersurfaces, whose components intersect
in a transversal way but may be themselves singular. Such hypersurfaces will be
called splayed divisors. A splayed divisor is characterized by a property of
its Jacobian ideal. This yields an effective test for splayedness. Two further
characterizations of a splayed divisor are shown, one reflecting the geometry
of the intersection of its components, the other one using K. Saito's
logarithmic derivations. As an application we prove that a union of smooth
hypersurfaces has normal crossings if and only if it is a free divisor and has
a radical Jacobian ideal. Further it is shown that the Hilbert-Samuel
polynomials of splayed divisors satisfy a certain additivity property.Comment: 15 pages, 1 figure; v2: minor revision: inaccuracies corrected and
references updated; v3: final version, to appear in Publ. RIM

### Charges and Electromagnetic radiation as topological excitations

We discuss a model with stable topological solitons in Minkowski space with
only three degrees of freedom, the rotational angles of a spatial Dreibein.
This model has four types of solitons differing in two topological quantum
numbers which we identify with electric charge and spin. The vacuum has a
two-dimensional degeneracy leading to two types of massless excitations,
characterised by a topological quantum number which could have a physical
equivalent in the photon number.Comment: 9 page

### A Model for Topological Fermions

We introduce a model designed to describe charged particles as stable
topological solitons of a field with values on the internal space S^3. These
solitons behave like particles with relativistic properties like Lorentz
contraction and velocity dependence of mass. This mass is defined by the energy
of the soliton. In this sense this model is a generalisation of the sine-Gordon
model from 1+1 dimensions to 3+1 dimensions, from S^1 to S^3. (We do not chase
the aim to give a four-dimensional generalisation of Coleman's isomorphism
between the Sine-Gordon model and the Thirring model which was shown in
2-dimensional space-time.) For large distances from the center of solitons this
model tends to a dual U(1)-theory with freely propagating electromagnetic
waves. Already at the classical level it describes important effects, which
usually have to be explained by quantum field theory, like
particle-antiparticle annihilation and the running of the coupling.Comment: 42 pages, 7 figures, more detailed calculations and comparison to
Skyrme model and 't Hooft-Polyakov monopoles adde

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