4,579 research outputs found
Loop Variables and the Interacting Open String in a Curved Background
Applying the loop variable proposal to a sigma model (with boundary) in a
curved target space, we give a systematic method for writing the gauge and
generally covariant interacting equations of motion for the modes of the open
string in a curved background. As in the free case described in an earlier
paper, the equations are obtained by covariantizing the flat space (gauge
invariant) interacting equations and then demanding gauge invariance in the
curved background. The resulting equation has the form of a sum of terms that
would individually be gauge invariant in flat space or at zero interaction
strength, but mix amongst themselves in curved space when interactions are
turned on. The new feature is that the loop variables are deformed so that
there is a mixing of modes. Unlike the free case, the equations are coupled,
and all the modes of the open string are required for gauge invariance.Comment: 11 pages, Late
Dyons of One Half Monopole Charge
We would like to present some exact SU(2) Yang-Mills-Higgs dyon solutions of
one half monopole charge. These static dyon solutions satisfy the first order
Bogomol'nyi equations and are characterized by a parameter, . They are
axially symmetric. The gauge potentials and the electromagnetic fields possess
a string singularity along the negative z-axis and hence they possess infinite
energy density along the line singularity. However the net electric charges of
these dyons which varies with the parameter are finite.Comment: 16 pages, 7 figure
Generalized Jacobi Elliptic One-Monopole - Type A
We present new classical generalized one-monopole solution of the SU(2)
Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. We
show that this generalized solution with -winding number and
-winding number is an axially symmetric Jacobi elliptic
generalization of the 't Hooft-Polyakov one-monopole. We construct this axially
symmetric one-monopole solution by generalizing the large distance asymptotic
solution of the 't Hooft-Polyakov one-monopole to the Jacobi elliptic functions
and solving the second order equations of motion numerically when the Higgs
potential is vanishing and non vanishing. These solutions are regular non-BPS
finite energy solutions.Comment: 17 pages, 5 figure
Five-dimensional Monopole Equation with Hedge-Hog Ansatz and Abel's Differential Equation
We review the generalized monopole in the five-dimensional Euclidean space. A
numerical solution with the Hedge-Hog ansatz is studied. The Bogomol'nyi
equation becomes a second order autonomous non-linear differential equation.
The equation can be translated into the Abel's differential equation of the
second kind and is an algebraic differential equation.Comment: 4 pages, 4 figures, typos correcte
Electric Flux Tube in Magnetic Plasma
In this paper we study a methodical problem related to the magnetic scenario
recently suggested and initiated by the authors \cite{Liao_ES_mono} to
understand the strongly coupled quark-gluon plasma (sQGP): the electric flux
tube in monopole plasma. A macroscopic approach, interpolating between Bose
condensed (dual superconductor) and classical gas medium is developed first.
Then we work out a microscopic approach based on detailed quantum mechanical
calculation of the monopole scattering on electric flux tube, evaluating
induced currents for all partial waves. As expected, the flux tube looses its
stability when particles can penetrate it: we make this condition precise by
calculating the critical value for the product of the flux tube size times the
particle momentum, above which the flux tube dissolves. Lattice static
potentials indicate that flux tubes seem to dissolve at . Using our criterion one gets an estimate of the magnetic
density at this temperature.Comment: New version with new referecences added and minor changes. 15 pages,
8 figure
Non-Abelian Semilocal Strings in N=2 Supersymmetric QCD
We consider a benchmark bulk theory in four-dimensions: N=2 supersymmetric
QCD with the gauge group U(N) and N_f flavors of fundamental matter
hypermultiplets (quarks). The nature of the BPS strings in this benchmark
theory crucially depends on N_f. If N_f\geq N and all quark masses are equal,
it supports non-Abelian BPS strings which have internal (orientational) moduli.
If N_f>N these strings become semilocal, developing additional moduli \rho
related to (unlimited) variations of their transverse size.
Using the U(2) gauge group with N_f=3,4 as an example, we derive an effective
low-energy theory on the (two-dimensional) string world sheet. Our derivation
is field-theoretic, direct and explicit: we first analyze the Bogomol'nyi
equations for string-geometry solitons, suggest an ansatz and solve it at large
\rho. Then we use this solution to obtain the world-sheet theory.
In the semiclassical limit our result confirms the Hanany-Tong conjecture,
which rests on brane-based arguments, that the world-sheet theory is N=2
supersymmetric U(1) gauge theory with N positively and N_e=N_f-N negatively
charged matter multiplets and the Fayet-Iliopoulos term determined by the
four-dimensional coupling constant. We conclude that the Higgs branch of this
model is not lifted by quantum effects. As a result, such strings cannot
confine.
Our analysis of infrared effects, not seen in the Hanany-Tong consideration,
shows that, in fact, the derivative expansion can make sense only provided the
theory under consideration is regularized in the infrared, e.g. by the quark
mass differences. The world-sheet action discussed in this paper becomes a bona
fide low-energy effective action only if \Delta m_{AB}\neq 0.Comment: 36 pages, no figure
CP Violation from a Higher Dimensional Model
It is shown that Randall-Sundrum model has the EDM term which violates the
CP-symmetry. The comparison with the case of Kaluza-Klein theory is done. The
chiral property, localization, anomaly phenomena are examined. We evaluate the
bulk quantum effect using the method of the induced effective action. This is a
new origin of the CP-violation.Comment: 15pages, Proc. of Int. Workshop on "Neutrino Masses and
Mixings"(Dec.17-19,2006,Univ.of Shizuoka,Japan
Normalized Ricci flow on Riemann surfaces and determinants of Laplacian
In this note we give a simple proof of the fact that the determinant of
Laplace operator in smooth metric over compact Riemann surfaces of arbitrary
genus monotonously grows under the normalized Ricci flow. Together with
results of Hamilton that under the action of the normalized Ricci flow the
smooth metric tends asymptotically to metric of constant curvature for , this leads to a simple proof of Osgood-Phillips-Sarnak theorem stating that
that within the class of smooth metrics with fixed conformal class and fixed
volume the determinant of Laplace operator is maximal on metric of constant
curvatute.Comment: a reference to paper math.DG/9904048 by W.Mueller and K.Wendland
where the main theorem of this paper was proved a few years earlier is adde
Connection between the Loop Variable Formalism and the Old Covariant Formalsm for the Open Bosonic String
The gauge invariant loop variable formalism and old covariant formalism for
bosonic open string theory are compared in this paper. It is expected that for
the free theory, after gauge fixing, the loop variable fields can be mapped to
those of the old covariant formalism in bosonic string theory, level by level.
This is verified explicitly for the first two massive levels. It is shown that
(in the critical dimension) the fields, constraints and gauge transformations
can all be mapped from one to the other. Assuming this continues at all levels
one can give general arguments that the tree S-matrix (integrated correlation
functions for on-shell physical fields) is the same in both formalisms and
therefore they describe the same physical theory (at tree level).Comment: Latex file, 24 page
Instability of (1+1) de sitter space in the presence of interacting fields
Instabilities of two dimensional (1+1) de Sitter space induced by interacting
fields are studied. As for the case of flat Minkowski space, several
interacting fermion models can be translated into free boson ones and vice
versa. It is found that interacting fermion theories do not lead to any
instabilities, while the interacting bosonic sine-Gordon model does lead to a
breakdown of de Sitter symmetry and to the vanishing of the vacuum expectation
value of the S matrix.Comment: 7 page
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