302 research outputs found

    Hamiltonian Approach to 2D Dilaton-Gravities and Invariant Adm Mass

    Full text link
    The formula existing in the literature for the ADM mass of 2D dilaton gravity is incomplete. For example, in the case of an infalling matter shockwave this formula fails to give a time-independent mass, unless a very special coordinate system is chosen. We carefully carry out the canonical formulation of 2D dilaton gravity theories (classical, CGHS and RST). As in 4D general relativity one must add a boundary term to the bulk Hamiltonian to obtain a well-defined variational problem. This boundary term coincides with the numerical value of the Hamiltonian and gives the correct mass which obviously is time-independent.Comment: revised, 12 pages, PUPT-1379; we added a reference and corrected some minor typo

    On the Interacting Chiral Gauge Field Theory in D=6 and the Off-Shell Equivalence of Dual Born-Infeld-Like Actions

    Get PDF
    A canonical action describing the interaction of chiral gauge fields in D=6 Minkowski space-time is constructed. In a particular partial gauge fixing it reduces to the action found by Perry and Schwarz. The additional gauge symmetries are used to show the off-shell equivalence of the dimensional reduction to D=5 Minkowski space-time of the chiral gauge field canonical action and the Born-Infeld canonical action describing an interacting D=5 Abelian vector field. Its extension to improve the on-shell equivalence arguments of dual D-brane actions to off-shell ones is discussed.Comment: 18 page

    Coupling of branes and normalization of effective actions in string/M-theory

    Get PDF
    We discuss issues involving p(D)- brane charge quantization and the normalization of effective actions, in string/M-theory. We also construct the action of (the bosonic sector of) eleven dimensional supergravity in the presence of two- and five- branes and discuss (perturbative) anomaly cancellation.Comment: Discussion of anomaly cancellation expanded. 36 pages, latex, no figure

    Creation of Fundamental Strings by Crossing D-branes

    Get PDF
    We study the force balance between orthogonally positioned pp-brane and (8−p)(8-p)-brane. The force due to graviton and dilaton exchange is repulsive in this case. We identify the attractive force that balances this repulsion as due to one-half of a fundamental string stretched between the branes. As the pp-brane passes through the (8−p)(8-p)-brane, the connecting string changes direction, which may be interpreted as creation of one fundamental string. We show this directly from the structure of the Chern-Simons terms in the D-brane effective actions. We also discuss the effect of string creation on the 0-brane quantum mechanics in the type I' theory. The creation of a fundamental string is related by U-duality to the creation of a 3-brane discussed by Hanany and Witten. Both processes have a common origin in M-theory: as two M5-branes with one common direction cross, a M2-brane stretched between them is created.Comment: 6 pages, Late

    On the Supergravity Gauge theory Correspondence and the Matrix Model

    Get PDF
    We review the assumptions and the logic underlying the derivation of DLCQ Matrix models. In particular we try to clarify what remains valid at finite NN, the role of the non-renormalization theorems and higher order terms in the supergravity expansion. The relation to Maldacena's conjecture is also discussed. In particular the compactification of the Matrix model on T3T_3 is compared to the AdS5×S5AdS_5\times S_5 N=4{\cal N}=4 super Yang-Mills duality, and the different role of the branes in the two cases is pointed out.Comment: 19 pages, Late

    Travel Planning Management System

    Get PDF
    This project, "TRAVEL PLANNING MANAGEMENT SYSTEM", is used to automate all processes of travel and tourism, which deals with the creation, booking, confirmation, and user details. The project is designed with React JS as the front end and Spring boot as the backend, which works in any browser. A travel planning management system is used to book a tour from anywhere in the world by a single dynamic website which will help the user to know all about the places and travel details in a single web application. The admin can add travel packages to the system, transport services, place management, and hotels to create travel packages. Then the users can sign in and book each travel package, and also, they can book custom travel packages. The user can confirm their bookings by paying for the package. It is the most accessible platform for travellers who can easily book and know all details

    Moduli Redefinitions and Moduli Stabilisation

    Full text link
    Field redefinitions occur in string compactifications at the one loop level. We review arguments for why such redefinitions occur and study their effect on moduli stabilisation and supersymmetry breaking in the LARGE volume scenario. For small moduli, although the effect of such redefinitions can be larger than that of the α′\alpha' corrections in both the K\"ahler and scalar potentials, they do not alter the structure of the scalar potential. For the less well motivated case of large moduli, the redefinitions can dominate all other terms in the scalar potential. We also study the effect of redefinitions on the structure of supersymmetry breaking and soft terms.Comment: 21 pages, 3 figures; v2. references adde

    Bosonic Quadratic Actions for 11D Supergravity on AdS_7/4 x S_4/7

    Full text link
    We determine from 11D supergravity the quadratic bulk action for the physical bosonic fields relevant for the computation of correlation functions of normalized chiral operators in D=6, N=(0,2) and D=3, N=8 supersymmetric CFT in the large N limit, as dictated by the AdS/CFT duality conjecture.Comment: 16 pages, Plain TeX, no figures, requires AMS font files amssym.def and amssym.tex, a few typos correcte

    Light-Cone Quantization of the Liouville Model

    Full text link
    We present the quantization of the Liouville model defined in light-cone coordinates in (1,1) signature space. We take advantage of the representation of the Liouville field by the free field of the Backl\"{u}nd transformation and adapt the approch by Braaten, Curtright and Thorn. Quantum operators of the Liouville field ∂+ϕ\partial_{+}\phi, ∂−ϕ\partial_{-}\phi, egϕe^{g\phi}, e2gϕe^{2g\phi} are constructed consistently in terms of the free field. The Liouville model field theory space is found to be restricted to the sector with field momentum P+=−P−P_{+}=-P_{-}, P+>0P_{+}> 0 , which is a closed subspace for the Liouville theory operator algebra.Comment: 16 p, EFI-92-6

    Potent Trivalent Inhibitors of Thrombin through Hybridization of Salivary Sulfopeptides from Hematophagous Arthropods

    Get PDF
    Blood feeding arthropods, such as leeches, ticks, flies and mosquitoes, provide a privileged source of peptidic anticoagulant molecules. These primarily operate through inhibition of the central coagulation protease thrombin by binding to the active site and either exosite I or exosite II. Herein, we describe the rational design of a novel class of trivalent thrombin inhibitors that simultaneously block both exosites as well as the active site. These engineered hybrids were synthesized using tandem diselenide-selenoester ligation (DSL) and native chemical ligation (NCL) reactions in one-pot. The most potent trivalent inhibitors possessed femtomolar inhibition constants against alpha-thrombin and were selective over related coagulation proteases. A lead hybrid inhibitor possessed potent anticoagulant activity, blockade of both thrombin generation and platelet aggregation in vitro and efficacy in a murine thrombosis model at 1 mg kg(-1). The rational engineering approach described here lays the foundation for the development of potent and selective inhibitors for a range of other enzymatic targets that possess multiple sites for the disruption of protein-protein interactions, in addition to an active site
    • …
    corecore