284 research outputs found
A Note on Effective String Theory
Motivated by the possibility of an effective string description for the
infrared limit of pure Yang-Mills theory, we present a toy model for an
effective theory of random surfaces propagating in a target space of . We
show that the scaling exponents for the fixed area partition function of the
theory are apparently well behaved. We make some observations regarding the
usefulness of this toy model.Comment: 17 pages, LATEX, UTTG-21-9
Spin and Rotations in Galois Field Quantum Mechanics
We discuss the properties of Galois Field Quantum Mechanics constructed on a
vector space over the finite Galois field GF(q). In particular, we look at
2-level systems analogous to spin, and discuss how SO(3) rotations could be
embodied in such a system. We also consider two-particle `spin' correlations
and show that the Clauser-Horne-Shimony-Holt (CHSH) inequality is nonetheless
not violated in this model.Comment: 21 pages, 11 pdf figures, LaTeX. Uses iopart.cls. Revised
introduction. Additional reference
Spacetime Emergence and General Covariance Transmutation
Spacetime emergence refers to the notion that classical spacetime "emerges"
as an approximate macroscopic entity from a non-spatio-temporal structure
present in a more complete theory of interacting fundamental constituents. In
this article, we propose a novel mechanism involving the "soldering" of
internal and external spaces for the emergence of spacetime and the twin
transmutation of general covariance. In the context of string theory, this
mechanism points to a critical four dimensional spacetime background.Comment: 11 pages, v2: version to appear in MPL
Background Independent Quantum Mechanics and Gravity
We argue that the demand of background independence in a quantum theory of
gravity calls for an extension of standard geometric quantum mechanics. We
discuss a possible kinematical and dynamical generalization of the latter by
way of a quantum covariance of the state space. Specifically, we apply our
scheme to the problem of a background independent formulation of Matrix Theory.Comment: 9 pages, LaTe
Superintegrable Systems, Multi-Hamiltonian Structures and Nambu Mechanics in an Arbitrary Dimension
A general algebraic condition for the functional independence of 2n-1
constants of motion of an n-dimensional maximal superintegrable Hamiltonian
system has been proved for an arbitrary finite n. This makes it possible to
construct, in a well-defined generic way, a normalized Nambu bracket which
produces the correct Hamiltonian time evolution. Existence and explicit forms
of pairwise compatible multi-Hamiltonian structures for any maximal
superintegrable system have been established. The Calogero-Moser system, motion
of a charged particle in a uniform perpendicular magnetic field and
Smorodinsky-Winternitz potentials are considered as illustrative applications
and their symmetry algebras as well as their Nambu formulations and alternative
Poisson structures are presented.Comment: 20 pages, 1 table (submitted for publication
On the Nonperturbative Consistency of String Theory
An infinite number of distinct matrix models reproduce the perturbation
theory of string theory. Due to constraints of causality, however, we
argue that none of the existing constructions gives a consistent
nonperturbative definition of the string.Comment: 10 pages, 2 figures, LaTeX (author's name added
Fuzzy Gravitons From Uncertain Spacetime
The recently proposed remarkable mechanism explaining ``stringy exclusion
principle" on an Anti de Sitter space is shown to be another beautiful
manifestation of spacetime uncertainty principle in string theory as well as in
M theory. Put in another way, once it is realized that the graviton of a given
angular momentum is represented by a spherical brane, we deduce the maximal
angular momentum directly from either the relation
in M theory or \Delta t\Delta x>\ap in string theory. We also show that the
result of hep-th/0003075 is similar to results on D2-branes in SU(2) WZW model.
Using the dual D2-brane representation of a membrane, we obtain the
quantization condition for the size of the membrane.Comment: 10 pages, harvmac. v2: a ref. and a note added; v3: A remark and one
more ref. adde
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