729 research outputs found
Induced Polyakov supergravity on Riemann surfaces of higher genus
An effective action is obtained for the , induced supergravity on a
compact super Riemann surface (without boundary) of genus ,
as the general solution of the corresponding superconformal Ward identity. This
is accomplished by defining a new super integration theory on
which includes a new formulation of the super Stokes theorem and residue
calculus in the superfield formalism. Another crucial ingredient is the notion
of polydromic fields. The resulting action is shown to be well-defined and free
of singularities on \sig. As a by-product, we point out a morphism between
the diffeomorphism symmetry and holomorphic properties.Comment: LPTB 93-10, Latex file 20 page
On the holomorphic factorization for superconformal fields
For a generic value of the central charge, we prove the holomorphic
factorization of partition functions for free superconformal fields which are
defined on a compact Riemann surface without boundary. The partition functions
are viewed as functionals of the Beltrami coefficients and their fermionic
partners which variables parametrize superconformal classes of metrics.Comment: 5 pages, LATEX, MPI-Ph/92-7
The Polyakov action on the supertorus
A consistent method for obtaining a well-defined Polyakov action on the
supertorus is presented. This method uses the covariantization of derivative
operators and enables us to construct a Polyakov action which is globally
defined.Comment: 15 pages LaTe
d=2, N=2 Superconformal Symmetries and Models
We discuss the following aspects of two-dimensional N=2 supersymmetric
theories defined on compact super Riemann surfaces: parametrization of (2,0)
and (2,2) superconformal structures in terms of Beltrami coefficients and
formulation of superconformal models on such surfaces (invariant actions,
anomalies and compensating actions, Ward identities).Comment: 43 pages, late
Response of Broiler Chickens in the Starter and Finisher Phases to 3 Sources of Microbial Phytase
A broiler chicken study was conducted for 42 D to evaluate their responses to 3 commercially available microbial phytases. Growth performance, nutrient digestibility, and bone mineralization at days 21 and 42 posthatching were used as parameters of evaluation. The study was a randomized complete block design with 12 treatments, 8 replicate pens, and 25 birds per pen. Treatments included a positive control (PC), a negative control (NC) with crude protein (CP), nonphytate phosphorus (P), and calcium (Ca) reduced by 18, 1.5, and 1.8 g/kg, respectively; the NC + 4 levels of phytase A (250, 500, 750, 1,000 FTU/kg), 3 levels of phytase B (250, 500, 750 FTU/kg), and 3 levels of phytase C (500, 750, 1,000 FTU/kg). Broilers fed the NC diet had reduced (P \u3c 0.05) performance and digestibility measures at days 21 and 42 relative to the PC. All phytase enzymes improved (P \u3c 0.05) BW, gain, feed efficiency, and tibia ash weight and percent. Inclusion of phytase at the highest levels improved (P \u3c 0.05) tibia ash weight by an average of 18.5 and 22% at days 21 and 42, respectively, over the NC. Phytase A linearly improved (P \u3c 0.05) the apparent ileal digestibility (AID) of DM, Ca, P, copper, and sodium at day 21, and the AID of energy, nitrogen, and all amino acid (AA) digestibility at day 42 posthatching. Phytase B linearly (P \u3c 0.05) improved BW gain and feed efficiency of birds at day 21 and quadratically improved (P \u3c 0.05) the AID of nitrogen and all AA in birds at day 42. Supplementation of birds fed the NC with phytase C linearly improved (P \u3c 0.05) the BW gain, feed intake, feed efficiency, and AID of DM, energy, nitrogen, all AA, and all minerals except manganese at day 42. In conclusion, all 3 phytase products improved the growth performance, nutrient and mineral digestibility, and bone mineralization of birds fed diets deficient in nitrogen, Ca, and P similar to or more than birds fed diet adequate in P and CP
W-algebras from symplectomorphisms
It is shown how -algebras emerge from very peculiar canonical
transformations with respect to the canonical symplectic structure on a compact
Riemann surface. The action of smooth diffeomorphisms of the cotangent bundle
on suitable generating functions is written in the BRS framework while a
-symmetry is exhibited. Subsequently, the complex structure of the symmetry
spaces is studied and the related BRS properties are discussed. The specific
example of the so-called -algebra is treated in relation to some other
different approaches.Comment: LaTex, 25 pages, no figures, to appear in Journ. Math. Phy
Supersymmetric structure of the induced W gravities
We derive the supersymmetric structure present in W-gravities which has been
already observed in various contexts as Yang-Mills theory, topological field
theories, bosonic string and chiral W_{3}-gravity. This derivation which is
made in the geometrical framework of Zucchini, necessitates the introduction of
an appropriate new basis of variables which replace the canonical fields and
their derivatives. This construction is used, in the W_{2}-case, to deduce from
the Chern-Simons action the Wess-Zumino-Polyakov action.Comment: 17 pages, Latex. To appear in Class. Quantum. Gravit
Search for Flavoured Multiquarks in a Simple Bag Model
We use a bag model to study flavoured mesonic and baryonic
states, where one heavy quark is associated with
light quarks or antiquarks, and search for possible stable multiquarks. No
bound state is found. However some states lie not too high above their
dissociation threshold, suggesting the possibility of resonances, or perhaps
bound states in improved models.Comment: REVTEX, VERSION 3.
New Lower Bound on Fermion Binding Energies
We derive a new lower bound for the ground state energy of N
fermions with total spin S in terms of binding energies of (N-1) fermions. Numerical examples are provided for some simple
short-range or confining potentials.Comment: 4 pages, 1 eps figur
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