89 research outputs found
Gravity and Duality between Coordinates and Matter Fields
We use the duality between the local Cartezian coordinates and the solutions
of the Klein-Gordon equation to parametrize locally the spacetime in terms of
wave functions and prepotentials. The components of metric, metric connection,
curvature as well as the Einstein equation are given in this parametrization.
We also discuss the local duality between coordinates and quantum fields and
the metric in this later reparametrization.Comment: 11 pages, REVTeX file, a new paragraph added, to be published in
Phys. Lett.
On Local Constraints of D=4 Supergravity in Terms of Dirac Eigenvalues
It has been recently shown that in order to have Dirac eigenvalues as
observables of Euclidean supergravity, certain constraints should be imposed on
the covariant phase space as well as on Dirac eigenspinors. We investigate the
relationships among the constraints in the first set and argue that these
relationships are not linear. We also derive a set of equations expressing the
linear dependency of the constraints in order that the second set of
constraints be linearly independent.Comment: 7 pages, REVTeX file, to be published in Mod. Phys. Lett.
Entropic Law of Force, Emergent Gravity and the Uncertainty Principle
The entropic formulation of the inertia and the gravity relies on quantum,
geometrical and informational arguments. The fact that the results are
completly classical is missleading. In this paper we argue that the entropic
formulation provides new insights into the quantum nature of the inertia and
the gravity. We use the entropic postulate to determine the quantum uncertainty
in the law of inertia and in the law of gravity in the Newtonian Mechanics, the
Special Relativity and in the General Relativity. These results are obtained by
considering the most general quantum property of the matter represented by the
Uncertainty Principle and by postulating an expression for the uncertainty of
the entropy such that: i) it is the simplest quantum generalization of the
postulate of the variation of the entropy and ii) it reduces to the variation
of the entropy in the absence of the uncertainty.Comment: 10 pages. Important discussion of the special relativistic case and
the newtonian limit of the general relativistic case added. The paper has
been reformatted. The authorship listing corrected. (It has been published by
mistake out of order in the first version. We have been adhering to the
Hardy-Littlewood Rule over the years.) Typos corrected. Four references adde
Introductory Lectures on D-Branes
This is a pedagogical introduction to D-branes, addressed to graduate
students in field theory and particle physics and to other beginners in string
theory. I am not going to review the most recent results since there are
already many good papers on web devoted to that. Instead, I will present some
old techniques in some detail in order to show how some basic properties of
strinfs and branes as the massless spectrum of string, the effective action of
D-branes and their tension can be computed using QFT techniques. Also, I will
present shortly the boundary state description of D-branes. The details are
exposed for bosonic branes since I do not assume any previous knowledge of
supersymmetry which is not a requirement for this school. However, for
completeness and to provide basic notions for other lectures, I will discuss
some properties of supersymemtric branes. The present lectures were delivered
at Jorge Andr\'{e} Swieca School on Particle and Fields, 2001, Campos do
Jord\~{a}o, Brazil.Comment: 49 pages, LATeX file, some minor errors corrected and references
adde
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