1,256 research outputs found
BPS surface observables in six-dimensional (2,0) theory
The supergroup OSp(8*|4), which is the superconformal group of (2,0) theory
in six dimensions, is broken to the subgroup OSp(4|2)xOSp(4|2) by demanding the
invariance of a certain product in a superspace with eight bosonic and four
fermionic dimensions. We show that this is consistent with the symmetry
breaking induced by the presence of a flat two-dimensional BPS surface in the
usual (2,0) superspace, which has six bosonic and sixteen fermionic dimensions.Comment: 9 pages, LaTeX. v2: reference adde
Manifest superconformal covariance in six-dimensional (2,0) theory
A superconformal generalization of Dirac's formalism for manifest conformal
covariance is presented and applied to the free (2,0) tensor multiplet field
theory in six dimensions. A graded symmetric superfield, defined on a supercone
in a higher-dimensional superspace is introduced. This superfield transforms
linearly under the transformations of the supergroup OSp(8*|4), which is the
superconformal group of the six-dimensional (2,0) theory. We find the
relationship between the new superfield and the conventional (2,0) superfields
in six dimensions and show that the implied superconformal transformation laws
are correct. Finally, we present a manifestly conformally covariant constraint
on the supercone, which reduces to the ordinary differential constraint for the
superfields in the six-dimensional space-time.Comment: 12 pages, LaTeX. v2: minor clarification adde
Supersymmetric coupling of a self-dual string to a (2,0) tensor multiplet background
We construct an interaction between a (2,0) tensor multiplet in six
dimensions and a self-dual string. The interaction is a sum of a Nambu-Goto
term, with the tension of the string given by the modulus of the scalar fields
of the tensor multiplet, and a non-local Wess-Zumino term, that encodes the
electromagnetic coupling of the string to the two-form gauge field of the
tensor multiplet. The interaction is invariant under global (2,0)
supersymmetry, modulo the equations of motion of a free tensor multiplet. It is
also invariant under a local fermionic kappa-symmetry, as required by the
BPS-property of the string.Comment: 12 pages, LaTe
Harvesting Silage With Two Types of Silage Trailer (Feed Rotor With Knives and Precision Chop)
Harvesting silage with a silage trailer that combines both a precision chopper and a trailer in the same machine is common in Sweden. A silage trailer with a feed rotor and knives has recently been put on the market. The objective of this study was to compare the two system
Energy radiated from a fluctuating selfdual string
We compute the energy that is radiated from a fluctuating selfdual string in
the large limit of theory using the AdS-CFT correspondence. We
find that the radiated energy is given by a non-local expression integrated
over the string world-sheet. We also make the corresponding computation for a
charged string in six-dimensional classical electrodynamics, thereby
generalizing the Larmor formula for the radiated energy from an accelerated
point particle.Comment: 12 page
Free tensor multiplets and strings in spontaneously broken six-dimensional (2,0) theory
We first review the representations of the six-dimensional (2,0) superalgebra
on a free tensor multiplet and on a free string. We then construct a
supersymmetric Lagrangian describing a free tensor multiplet. (It also includes
a decoupled anti self-dual part of the three-form field strength.) This field
theory is then rewritten in variables appropriate for analyzing a situation
where the R-symmetry is spontaneously broken by the vacuum expectation values
of the scalar moduli fields. Finally, we construct a supersymmetric and
kappa-symmetric action for a free string.Comment: 15 pages, LaTe
Classical self-dual strings in d=6, (2,0) theory from afar
We show how one can get solitonic strings in a six-dimensional (2,0)
supersymmetric theory by incorporating a nonlinear interaction term. We derive
a zero force condition between parallel strings, and compute a metric on a
moduli space which is when the strings are far apart. When compactifying
the strings on a two-torus we show that, in the limit of vanishing two-torus,
one regains the moduli space of two widely separated dyons of equal magnetic
charges in four dimensions.Comment: 13 pages, clarifications and added reference
Conformal anomaly of Wilson surface observables - a field theoretical computation
We make an exact field theoretical computation of the conformal anomaly for
two-dimensional submanifold observables. By including a scalar field in the
definition for the Wilson surface, as appropriate for a spontaneously broken
A_1 theory, we get a conformal anomaly which is such that N times it is equal
to the anomaly that was computed in hep-th/9901021 in the large N limit and
which relied on the AdS-CFT correspondence. We also show how the spherical
surface observable can be expressed as a conformal anomaly.Comment: 18 pages, V3: an `i' dropped in the Wilson surface, overall
normalization and misprints corrected, V4: overall normalization factor
corrected, references adde
Exercise-induced respiratory symptoms are not always asthma
AbstractEighty-eight patients with a history of exercise-induced respiratory symptoms performed a maximal exercise test in order to study the reasons for stopping the test. There was a wide range of percentage maximal fall in peak expiratory flow (PEF), from minus 3% to 63%, mean 11%, recorded 0–30 min, mean 12 min after the break. In the controls the maximal decrease was 0–16%, mean 6%. Diagnostic criteria for asthma were fulfilled by 48 patients (55%). Of these patients 42% had a fall in PEF ≥ 15% (exercise-induced asthma). Of the non-asthma patients 10% had a fall ≥ 15%. The most common reason for stopping the exercise in the asthma group was breathing troubles (46%), the most common reason in the non-asthma group was chest pain/discomfort (35%). In about 20% of the patients dizziness and/or pricking sensations in arms or legs indicated hyperventilation as an additional reason for stopping the exercise. It is concluded that other kinds of reaction, than bronchial obstruction such as breathing troubles not directly related to bronchial obstruction and chest pain, may be important factors that can restrict physical capacity in patients with exercise-induced respiratory symptoms
On instantons as Kaluza-Klein modes of M5-branes
Instantons and W-bosons in 5d maximally supersymmetric Yang-Mills theory
arise from a circle compactification of the 6d (2,0) theory as Kaluza-Klein
modes and winding self-dual strings, respectively. We study an index which
counts BPS instantons with electric charges in Coulomb and symmetric phases. We
first prove the existence of unique threshold bound state of (noncommutative)
U(1) instantons for any instanton number, and also show that charged instantons
in the Coulomb phase correctly give the degeneracy of SU(2) self-dual strings.
By studying SU(N) self-dual strings in the Coulomb phase, we find novel
momentum-carrying degrees on the worldsheet. The total number of these degrees
equals the anomaly coefficient of SU(N) (2,0) theory. We finally show that our
index can be used to study the symmetric phase of this theory, and provide an
interpretation as the superconformal index of the sigma model on instanton
moduli space.Comment: 54 pages, 2 figures. v2: references added, figure improved, added
comments on self-dual string anomaly, added new materials on the symmetric
phase index, other minor correction
- …