On Local Dilatation Invariance

The relationship between local Weyl scaling invariant models and local dilatation invariant actions is critically scrutinized. While actions invariant under local Weyl scalings can be constructed in a straightforward manner, actions invariant under local dilatation transformations can only be achieved in a very restrictive case. The invariant couplings of matter fields to an Abelian vector field carrying a non-trivial scaling weight can be easily built, but an invariant Abelian vector kinetic term can only be realized when the local scale symmetry is spontaneously broken.Comment: 3 page

Superspace Measures, Invariant Actions, and Component Projection Formulae for (2,2) Supergravity

In the framework of the prepotential description of superspace two-dimensional $(2,2)$ supergravity, we discuss the construction of invariant integrals. In addition to the full superspace measure, we derive the measure for chiral superspace, and obtain the explicit expressions for going from superspace actions to component actions. We consider both the minimal $U_A(1)$ and the extended $U_V(1) \otimes U_A(1)$ theories.Comment: 22 pages, Late

Dynamical Symmetries in q-deformed Quantum Mechanics

The dynamical algebra of the q-deformed harmonic oscillator is constructed. As a result, we find the free deformed Hamiltonian as well as the Hamiltonian of the deformed oscillator as a complicated, momentum dependent interaction Hamiltonian in terms of the usual canonical variables. Furthermore we construct a well-defined algebra SU$_q$(1,1) with consistent conjugation properties and comultiplication. We obtain non lowest weight representations of this algebra.Comment: 19 pages, latex, no figure

(Non)renormalizability of the D-deformed Wess-Zumino model

We continue the analysis of the $D$-deformed Wess-Zumino model which was started in the previous paper. The model is defined by a deformation which is non-hermitian and given in terms of the covariant derivatives $D_\alpha$. We calculate one-loop divergences in the two-point, three-point and four-point Green functions. We find that the divergences in the four-point function cannot be absorbed and thus our model is not renormalizable. We discuss possibilities to render the model renormalizable.Comment: 19 pages; version accepted for publication in Phys.Rev.D; new section with the detailed discussion on renormalizabilty added and a special choice of coupling constants which renders the model renormalizable analyze

The Gravitino-Overproduction Problem in Inflationary Universe

We show that the gravitino-overproduction problem is prevalent among inflation models in supergravity. An inflaton field \phi generically acquires (effective) non-vanishing auxiliary field G_\phi, if the K\"ahler potential is non-minimal. The inflaton field then decays into a pair of the gravitinos. We extensively study the cosmological constraints on G_\phi for a wide range of the gravitino mass. For many inflation models we explicitly estimate G_\phi, and show that the gravitino-overproduction problem severely constrains the inflation models, unless such an interaction as K = \kappa/2 |\phi|^2 z^2 + h.c. is suppressed (here z is the field responsible for the supersymmetry breaking). We find that many of them are already excluded or on the verge of, if \kappa \sim O(1).Comment: 34 pages, 7 figures. v2: minor correction

Thermal Gravitino Production and Collider Tests of Leptogenesis

Considering gravitino dark matter scenarios, we obtain the full gauge-invariant result for the relic density of thermally produced gravitinos to leading order in the Standard Model gauge couplings. For the temperatures required by thermal leptogenesis, we find gaugino mass bounds which will be probed at future colliders. We show that a conceivable determination of the gravitino mass will allow for a unique test of the viability of thermal leptogenesis in the laboratory.Comment: 5 pages, 3 figures, revised version matches published versio

Minimal Walking Technicolor: Set Up for Collider Physics

Different theoretical and phenomenological aspects of the Minimal and Nonminimal Walking Technicolor theories have recently been studied. The goal here is to make the models ready for collider phenomenology. We do this by constructing the low energy effective theory containing scalars, pseudoscalars, vector mesons and other fields predicted by the minimal walking theory. We construct their self-interactions and interactions with standard model fields. Using the Weinberg sum rules, opportunely modified to take into account the walking behavior of the underlying gauge theory, we find interesting relations for the spin-one spectrum. We derive the electroweak parameters using the newly constructed effective theory and compare the results with the underlying gauge theory. Our analysis is sufficiently general such that the resulting model can be used to represent a generic walking technicolor theory not at odds with precision data.Comment: 42 pages, 3 figures. RevTex forma

Probing R-parity violating models of neutrino mass at the LHC via top squark decays

It is shown that the R-parity violating decays of the lighter top squarks (${\widetilde t}_1$) triggered by the lepton number violating couplings $\lambda^{\prime}_{i33}$, where the lepton family index i = 1-3, can be observed at the LHC via the dilepton di-jet channel even if the coupling is as small as 10$^{-4}$ or 10$^{-5}$, which is the case in several models of neutrino mass, provided it is the next lightest supersymmetric particle(NLSP) the lightest neutralino being the lightest supersymmetric particle(LSP). We have first obtained a fairly model independent estimate of the minimum observable value of the parameter ($P_{ij} \equiv BR(\widetilde t \to l_i^+ b) \times BR(\widetilde t^* \to l_j^- \bar b$)) at the LHC for an integrated luminosity of 10fb$^{-1}$ as a function of \mlstop by a standard Pythia based analysis. We have then computed the parameter $P_{ij}$ in several representative models of neutrino mass constrained by the neutrino oscillation data and have found that the theoretical predictions are above the estimated minimum observable levels for a wide region of the parameter space.Comment: 19 pages, 1 Figure and 11 Table

Topological Defects in Twisted Bundles of Two-Dimensionally Ordered Filaments

Twisted assemblies of filaments in ropes, cables and bundles are essential structural elements in wide use in macroscopic materials as well as within the cells and tissues of living organisms. We develop the unique, non-linear elastic properties of twisted filament bundles that derive from generic properties of two-dimensional line-ordered materials. Continuum elasticity reveals a formal equivalence between the elastic stresses induced by bundle twist and those induced by the positive curvature in thin, elastic sheets. These geometrically-induced stresses can be screened by 5-fold disclination defects in lattice packing, and we predict a discrete spectrum elastic energy groundstates associated with integer numbers of disclinations in cylindrical bundles. Finally, we show that elastic-energy groundstates are extremely sensitive to defect position in the cross-section, with off-center disclinations driving the entire bundle to buckle, adopting globally writhing configurations.Comment: 4.1 pages; 3 figure

Supergravity and IOSp(3,1|4) gauge theory

A new formulation of simple D=4 supergravity in terms of the geometry of superspace is presented. The formulation is derived from the gauge theory of the inhomogeneous orthosymplectic group IOSp(3,1|4) on a (4,4)-dimensional base supermanifold by imposing constraints and taking a limit. Both the constraints and the limiting procedure have a clear {\it a priori} physical motivation, arising from the relationship between IOSp(3,1|4) and the super Poincar\'{e} group. The construction has similarities with the space-time formulation of Newtonian gravity.Comment: 17 pages. Expanded version. To appear in Class. Quantum Gra