585 research outputs found
N=2 Rigid Supersymmetry with Gauged Central Charge
We develop a general setting for N=2 rigid supersymmetric field theories with
gauged central charge in harmonic superspace. We consider those N=2 multiplets
which have a finite number of off-shell components and exist off shell owing to
a non-trivial central charge. This class includes, in particular, the
hypermultiplet with central charge and various versions of the vector-tensor
multiplet. For such theories we present a manifestly supersymmetric universal
action. Chern-Simons couplings to an external N=2 super Yang-Mills multiplet
are given, in harmonic superspace, for both the linear and nonlinear
vector-tensor multiplets with gauged central charge. We show how to deduce the
linear version of the vector-tensor multiplet from six dimensions.Comment: 46 pages, latex, no figure
Superform formulation for vector-tensor multiplets in conformal supergravity
The recent papers arXiv:1110.0971 and arXiv:1201.5431 have provided a
superfield description for vector-tensor multiplets and their Chern-Simons
couplings in 4D N = 2 conformal supergravity. Here we develop a superform
formulation for these theories. Furthermore an alternative means of gauging the
central charge is given, making use of a deformed vector multiplet, which may
be thought of as a variant vector-tensor multiplet. Its Chern-Simons couplings
to additional vector multiplets are also constructed. This multiplet together
with its Chern-Simons couplings are new results not considered by de Wit et al.
in hep-th/9710212.Comment: 28 pages. V2: Typos corrected and references updated; V3: References
updated and typo correcte
Perturbative Gravity in the Causal Approach
Quantum theory of the gravitation in the causal approach is studied up to the
second order of perturbation theory. We prove gauge invariance and
renormalizability in the second order of perturbation theory for the pure
gravity system (massless and massive). Then we investigate the interaction of
massless gravity with matter (described by scalars and spinors) and massless
Yang-Mills fields. We obtain a difference with respect to the classical field
theory due to the fact that in quantum field theory one cannot enforce the
divergenceless property on the vector potential and this spoils the
divergenceless property of the usual energy-momentum tensor. To correct this
one needs a supplementary ghost term in the interaction Lagrangian.Comment: 50 pages, no figures, some changes in the last sectio
The linear multiplet and ectoplasm
In the framework of the superconformal tensor calculus for 4D N=2
supergravity, locally supersymmetric actions are often constructed using the
linear multiplet. We provide a superform formulation for the linear multiplet
and derive the corresponding action functional using the ectoplasm method (also
known as the superform approach to the construction of supersymmetric
invariants). We propose a new locally supersymmetric action which makes use of
a deformed linear multiplet. The novel feature of this multiplet is that it
corresponds to the case of a gauged central charge using a one-form potential
not annihilated by the central charge (unlike the standard N=2 vector
multiplet). Such a gauge one-form can be chosen to describe a variant nonlinear
vector-tensor multiplet. As a byproduct of our construction, we also find a
variant realization of the tensor multiplet in supergravity where one of the
auxiliaries is replaced by the field strength of a gauge three-form.Comment: 31 pages; v3: minor corrections and typos fixed, version to appear in
JHE
Effect of egg turning and incubation time on carbonic anhydrase gene expression in the blastoderm of the Japanese quail (Coturnix c. japonica)
(1) The gene expression of carbonic anhydrase, a key enzyme for the production sub-embryonic fluid (SEF), was assessed in turned and unturned eggs of the Japanese quail. The plasma membrane-associated isoforms CA IV, CAIX, CA XII, CA XIV, and the cytoplasmic isoform CA II, were
investigated in the extra-embryonic tissue of the blastoderm and in embryonic blood.
(2) Eggs were incubated at 37.6C, c. 60% R.H., and turned hourly (90 ) or left unturned. From 48 to 96 hours of incubation mRNA was extracted from blastoderm tissue, reverse-transcribed to cDNA and quantified by real-time qPCR using gene-specific primers. Blood collected at 96h was processed identically.
(3) Blastoderm CAIV gene expression increased with the period of incubation only in turned eggs, with maxima at 84 and 96h of incubation. Only very low levels were found in blood.
(4) Blastoderm CA II gene expression was greatest at 48 and 54h of incubation, subsequently declining to much lower levels and una ected by turning. Blood CA II gene expression was about 25-fold greater than that in the blastoderm.
(5) The expression of CA IX in the blastoderm was the highest of all isoforms, yet unaffected by turning.
CA XII did not amplify and CA XIV was present at unquantifiable low levels.
(6) It is concluded that solely gene expression for CA IV is sensitive to egg turning, and that increased CA IV gene expression could account for the additional SEF mass found at 84-96h of incubation.
in embryos of turned eggs
(4,4) superfield supergravity
We present the N=4 superspace constraints for the two-dimensional (2d)
off-shell (4,4) supergravity with the superfield strengths expressed in terms
of a (4,4) twisted (scalar) multiplet TM-I, as well as the corresponding
component results, in a form suitable for applications. The constraints are
shown to be invariant under the N=4 super-Weyl transformations, whose N=4
superfield parameters form another twisted (scalar) multiplet TM-II. To solve
the constraints, we propose the Ansatz which makes the N=4 superconformal
flatness of the N=4 supergravity curved superspace manifest. The locally (4,4)
supersymmetric TM-I matter couplings, with the potential terms resulting from
spontaneous supersymmetry breaking, are constructed. We also find the full
(4,4) superconformally invariant (improved) TM-II matter action. The latter can
be extended to the (4,4) locally supersymmetric Liouville action which is
suitable for describing (4,4) supersymmetric non-critical strings.Comment: 32 pages, LaTeX, revised version (one reference added, and one
Appendix is reduced
Supergravity for Effective Theories
Higher-derivative operators are central elements of any effective field
theory. In supersymmetric theories, these operators include terms with
derivatives in the K\"ahler potential. We develop a toolkit for coupling such
supersymmetric effective field theories to supergravity. We explain how to
write the action for minimal supergravity coupled to chiral superfields with
arbitrary numbers of derivatives and curvature couplings. We discuss two
examples in detail, showing how the component actions agree with the
expectations from the linearized description in terms of a Ferrara-Zumino
multiplet. In a companion paper, we apply the formalism to the effective theory
of inflation.Comment: 26 page
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