The effect of Wilson line moduli on CP-violation by soft supersymmetry breaking terms

The CP-violating phases in the soft supersymmetry-breaking sector in orbifold compactifications with a continuous Wilson line are investigated. In this case the modular symmetry is the Siegel modular group $Sp(4,Z)$ of genus two. In particular, we study the case that the hidden sector non-perturbative superpotential is determined by the Igusa cusp form ${\cal C}_{12}$ of modular weight 12. The effect of large non-perturbative corrections to the dilaton K\"ahler potential on the resulting CP-violating phases is also investigated.Comment: LaTeX file, 12 pages plus 7 figures, to appear in Phys.Lett.

Time-dependent perturbations in two-dimensional String Black Holes

We discuss time-dependent perturbations (induced by matter fields) of a black-hole background in tree-level two-dimensional string theory. We analyse the linearized case and show the possibility of having black-hole solutions with time-dependent horizons. The latter exist only in the presence of time-dependent `tachyon' matter fields, which constitute the only propagating degrees of freedom in two-dimensional string theory. For real tachyon field configurations it is not possible to obtain solutions with horizons shrinking to a point. On the other hand, such a possibility seems to be realized in the case of string black-hole models formulated on higher world-sheet genera. We connect this latter result with black hole evaporation/decay at a quantum level.}Comment: 11 pages, two figures,UA-NPPS.9/92; CERN-TH.6671/9

Supersymmetric Polytropic Gas Dynamics

We construct the N=1 supersymmetric extension of the polytropic gas dynamics. We give both the Lagrangian as well as the Hamiltonian description of this system. We construct the infinite set of "Eulerian'' conserved charges associated with this system and show that they are in involution, thereby proving complete integrability of this system. We construct the SUSY -B extension of this system as well and comment on the similarities and differences between this system and an earlier construction of the supersymmetric Chaplygin gas. We also derive the N=1 supersymmetric extension of the elastic medium equations, which, however, do not appear to be integrable.Comment: 15 page

Quantum Mechanics and Black Holes in Four-Dimensional String Theory

In previous papers we have shown how strings in a two-dimensional target space reconcile quantum mechanics with general relativity, thanks to an infinite set of conserved quantum numbers, ``W-hair'', associated with topological soliton-like states. In this paper we extend these arguments to four dimensions, by considering explicitly the case of string black holes with radial symmetry. The key infinite-dimensional W-symmetry is associated with the $\frac{SU(1,1)}{U(1)}$ coset structure of the dilaton-graviton sector that is a model-independent feature of spherically symmetric four-dimensional strings. Arguments are also given that the enormous number of string {\it discrete (topological)} states account for the maintenance of quantum coherence during the (non-thermal) stringy evaporation process, as well as quenching the large Hawking-Bekenstein entropy associated with the black hole. Defining the latter as the measure of the loss of information for an observer at infinity, who - ignoring the higher string quantum numbers - keeps track only of the classical mass,angular momentum and charge of the black hole, one recovers the familiar a quadratic dependence on the black-hole mass by simple counting arguments on the asymptotic density of string states in a linear-dilaton background.Comment: 18 page

Duality and Global Symmetries

This is a general introduction to duality in field theories. The existence and breaking of global symmetries is used as a guideline to systematically prove duality between different field theories. Systems discussed include abelian and non-abelian T-duality in string theory, abelian and nonabelian bosonization, and duality for massless and massive antisymmetric tensor field theories in arbitrary number of dimensions. Open questions regarding these techniques are also discussed. (Lectures given at 33rd Karpacz Winter School `Duality: Strings and Fields' .)Comment: 19 pages,latex,espcrc

Preclinical Evaluation of a Novel In-111-Labeled Bombesin Homodimer for Improved Imaging of GRPR-Positive Prostate Cancer

<p>Rational-designed multimerization of targeting ligands can be used to improve kinetic and thermodynamic properties. Multimeric targeting ligands may be produced by tethering multiple identical or two or more monomeric ligands of different binding specificities. Consequently, multimeric ligands may simultaneously bind to multiple receptor molecules. Previously, multimerization has been successfully applied on radiolabeled RGD peptides, which resulted in an improved tumor targeting activity in animal models. Multimerization of peptide-based ligands may improve the binding characteristics by increasing local ligand concentration and by improving dissociation kinetics. Here, we present a preclinical study on a novel radiolabeled bombesin (BN) homodimer, designated In-111-DOTA-[(Aca-BN(7-14)](2), that was designed for enhanced targeting of gastrin-releasing peptide receptor (GRPR)-positive prostate cancer cells. A BN homodimer was conjugated with DOTA-NHS and labeled with In-111. After HPLC purification, the GRPR targeting ability of In-111-DOTA-[(Aca-BN(7-14)](2) was assessed by microSPECT imaging in SCUD mice xenografted with the human prostate cancer cell line PC-3. In-111 labeling of DOTA-[(Aca-BN(7-14)](2) was achieved within 30 min at 85 C with a labeling yield of >40%. High radiochemical purity (>95%) was achieved by HPLC purification. In-111-DOTA-[(Aca-BN(7-14)](2) specifically bound to GRPR-positive PC-3 prostate cancer cells with favorable binding characteristics because uptake of In-111-DOTA-[Aca-BN(7-14)](2) in GRPR-positive PC-3 cells increased over time. A maximum peak with 30% radioactivity was observed after 2 h of incubation. The log D value was -1.8 +/- 0.1. In-111-DOTA-[(Aca-BN(7-14)](2) was stable in vitro both in PBS and human serum for at least 4 days. In vivo biodistribution analysis and microSPECT/CT scans performed after 1, 4, and 24 h of injection showed favorable binding characteristics and tumor-to-normal tissue ratios. This study identifies In-111-DOTA-[(Aca-BN(7-14)](2) as a promising radiotracer for nuclear imaging of GRPR in prostate cancer.</p>