4,505 research outputs found
Subcritical Superstrings
We introduce the Liouville mode into the Green-Schwarz superstring. Like
massive supersymmetry without central charges, there is no kappa symmetry.
However, the second-class constraints (and corresponding Wess-Zumino term)
remain, and can be solved by (twisted) chiral superspace in dimensions D=4 and
6. The matter conformal anomaly is c = 4-D < 1. It thus can be canceled for
physical dimensions by the usual Liouville methods, unlike the bosonic string
(for which the consistency condition is c = D <= 1).Comment: 9 pg., compressed postscript file (.ps.Z), other formats (.dvi, .ps,
.ps.Z, 8-bit .tex) available at
http://insti.physics.sunysb.edu/~siegel/preprints/ or at
ftp://max.physics.sunysb.edu/preprints/siege
Snyder noncommutative space-time from two-time physics
We show that the two-time physics model leads to a mechanical system with
Dirac brackets consistent with the Snyder noncommutative space. An Euclidean
version of this space is also obtained and it is shown that both spaces have a
dual system describing a particle in a curved space-time.Comment: 5 pages, RevTeX4. References adde
Spectroscopy of a fractional Josephson vortex molecule
In long Josephson junctions with multiple discontinuities of the Josephson
phase, fractional vortex molecules are spontaneously formed. At each
discontinuity point a fractional Josephson vortex carrying a magnetic flux
, Wb being the magnetic flux
quantum, is pinned. Each vortex has an oscillatory eigenmode with a frequency
that depends on and lies inside the plasma gap.
We experimentally investigate the dependence of the eigenfrequencies of a
two-vortex molecule on the distance between the vortices, on their topological
charge and on the bias current applied to the
Josephson junction. We find that with decreasing distance between vortices, a
splitting of the eigenfrequencies occurs, that corresponds to the emergence of
collective oscillatory modes of both vortices. We use a resonant microwave
spectroscopy technique and find good agreement between experimental results and
theoretical predictions.Comment: submitted to Phys. Rev.
Composition and distribution of the peracarid crustacean fauna along a latitudinal transect off Victoria Land (Ross Sea, Antarctica) with special emphasis on the Cumacea
The following study was the first to describe composition and structure of the peracarid fauna systematically along a latitudinal transect off Victoria Land (Ross Sea, Antarctica). During the 19th Antarctic expedition of the Italian research vessel “Italica” in February 2004, macrobenthic samples were collected by means of a Rauschert dredge with a mesh size of 500 m at depths between 85 and 515 m. The composition of peracarid crustaceans, especially Cumacea was investigated. Peracarida contributed 63% to the total abundance of the fauna. The peracarid samples were dominated by amphipods (66%), whereas cumaceans were represented with 7%. Previously, only 13 cumacean species were known, now the number of species recorded from the Ross Sea increased to 34. Thus, the cumacean fauna of the Ross Sea, which was regarded as the poorest in terms of species richness, has to be considered as equivalent to that of other high Antarctic areas. Most important cumacean families concerning abundance and species richness were Leuconidae, Nannastacidae, and Diastylidae. Cumacean diversity was lowest at the northernmost area (Cape Adare). At the area off Coulman Island, which is characterized by muddy sediment, diversity was highest. Diversity and species number were higher at the deeper stations and abundance increased with latitude. A review of the bathymetric distribution of the Cumacea from the Ross Sea reveals that most species distribute across the Antarctic continental shelf and slope. So far, only few deep-sea records justify the assumption of a shallow-water–deep-sea relationship in some species of Ross Sea Cumacea, which is discussed from an evolutionary point of view
Weak continuous monitoring of a flux qubit using coplanar waveguide resonator
We study a flux qubit in a coplanar waveguide resonator by measuring
transmission through the system. In our system with the flux qubit decoupled
galvanically from the resonator, the intermediate coupling regime is achieved.
In this regime dispersive readout is possible with weak backaction on the
qubit. The detailed theoretical analysis and simulations give a good agreement
with the experimental data and allow to make the qubit characterization.Comment: 4 pages, 3 figures, to be published in Phys. Rev.
Molecular cloning, expression analysis and assignment of the porcine tumor necrosis factor superfamily member 10 gene (TNFSF10) to SSC13q34 -> q36 by fluorescence in situ hybridization and radiation hybrid mapping
We have cloned the complete coding region of the porcine TNFSF10 gene. The porcine TNFSF10 cDNA has an ORF of 870 nucleotides and shares 85 % identity with human TNFSF10, and 75% and 72% identity with rat and mouse Tnfsf10 coding sequences, respectively. The deduced porcine TNFSF10 protein consists of 289 amino acids with the calculated molecular mass of 33.5 kDa and a predicted pI of 8.15. The amino acid sequence similarities correspond to 86, 72 and 70% when compared with human, rat and mouse sequences, respectively. Nor-them blot analysis detected TNFSF10-specific transcripts (similar to 1.7 kb) in various organs of a 10-week-old pig, suggesting ubiquitous expression. Real-time RT-PCR studies of various organs from fetal (days 73 and 98) and postnatal stages (two weeks, eight months) demonstrated developmental and tissue-specific regulation of TNFSF10 mRNA abundance. The chromosomal location of the porcine TNFSF10 gene was determined by FISH of a specific BAC clone to metaphase chromosomes. This TNFSF10 BAC clone has been assigned to SSC13q34 -> q36. Additionally, the localization of the TNFSF10 gene was verified by RH mapping on the porcine IMpRH panel. Copyright (c) 2005S. KargerAG, Basel
Off-shell supergravity-matter couplings in three dimensions
We develop the superspace geometry of N-extended conformal supergravity in
three space-time dimensions. General off-shell supergravity-matter couplings
are constructed in the cases N=1,2,3,4.Comment: 73 pages; V5: typos in eqs. (3.4b), (3.17) and (4.24) correcte
Higher Structures in M-Theory
The key open problem of string theory remains its non-perturbative completion
to M-theory. A decisive hint to its inner workings comes from numerous
appearances of higher structures in the limits of M-theory that are already
understood, such as higher degree flux fields and their dualities, or the
higher algebraic structures governing closed string field theory. These are all
controlled by the higher homotopy theory of derived categories, generalised
cohomology theories, and -algebras. This is the introductory chapter
to the proceedings of the LMS/EPSRC Durham Symposium on Higher Structures in
M-Theory. We first review higher structures as well as their motivation in
string theory and beyond. Then we list the contributions in this volume,
putting them into context.Comment: 22 pages, Introductory Article to Proceedings of LMS/EPSRC Durham
Symposium Higher Structures in M-Theory, August 2018, references update
Six-dimensional Supergravity and Projective Superfields
We propose a superspace formulation of N=(1,0) conformal supergravity in six
dimensions. The corresponding superspace constraints are invariant under
super-Weyl transformations generated by a real scalar parameter. The known
variant Weyl super-multiplet is recovered by coupling the geometry to a
super-3-form tensor multiplet. Isotwistor variables are introduced and used to
define projective superfields. We formulate a locally supersymmetric and
super-Weyl invariant action principle in projective superspace. Some families
of dynamical supergravity-matter systems are presented.Comment: 39 pages; v3: some modifications in section 2; equations (2.3),
(2.14b), (2.16) and (2.17) correcte
- …