6,133 research outputs found
Proof of a Symmetrized Trace Conjecture for the Abelian Born-Infeld Lagrangian
In this paper we prove a conjecture regarding the form of the Born-Infeld
Lagrangian with a U(1)^2n gauge group after the elimination of the auxiliary
fields. We show that the Lagrangian can be written as a symmetrized trace of
Lorentz invariant bilinears in the field strength. More generally we prove a
theorem regarding certain solutions of unilateral matrix equations of arbitrary
order. For solutions which have perturbative expansions in the matrix
coefficients, the solution and all its positive powers are sums of terms which
are symmetrized in all the matrix coefficients and of terms which are
commutators.Comment: 9 pages, LaTeX, no figures, theorem generalized and a new method of
proof include
The upper atmosphere and ionosphere of Mars
The topics discussed include the following: the dynamic atmosphere of Mars; possible similarities with Earth and Venus; the atmosphere and ionosphere of Mars; solar wind interactions; future approved missions; and possible future mission
Nonabelian Gauge Theories on Noncommutative Spaces
In this paper, we describe a method for obtaining the nonabelian
Seiberg-Witten map for any gauge group and to any order in theta. The equations
defining the Seiberg-Witten map are expressed using a coboundary operator, so
that they can be solved by constructing a corresponding homotopy operator. The
ambiguities, of both the gauge and covariant type, which arise in this map are
manifest in our formalism.Comment: 14 pages, latex, Talk presented at 2001: A Spacetime Odyssey -
Michigan Center for Theoretical Physics, some typos correcte
Open String and Morita Equivalence of the Dirac-Born-Infeld Action with Modulus \Phi
Based on the canonical quantization of open strings ending on D-branes with a
background B field, we construct the open string propagator. We demonstrate the
relation between the T duality of the underlying string theory and the Morita
equivalence of the interpolating general Dirac-Born-Infeld theory on a
noncommutative torus in the nonzero modulus \Phi sector. The general
noncommutative Dirac-Born-Infeld action with the Wess-Zumino terms expressed by
the background R-R fields is shown to be Morita invariant.Comment: 10 pages, LaTex2e, no figure
First electrostatic probe results from Explorer 17
Electrostatic probe results from ionospheric sounding by Explorer XVII satellit
Spinarc gas tungsten arc torch holder
Semiautomatic welding torch enables operator to control arc length, torch angle, and spring tension when welding small diameter aluminum tubing. Tungsten is preset for the weld to make arc initiation easier and to eliminate searching for the joint through a dark welding lens
An Hilbert space approach for a class of arbitrage free implied volatilities models
We present an Hilbert space formulation for a set of implied volatility
models introduced in \cite{BraceGoldys01} in which the authors studied
conditions for a family of European call options, varying the maturing time and
the strike price an , to be arbitrage free. The arbitrage free
conditions give a system of stochastic PDEs for the evolution of the implied
volatility surface . We will focus on the family obtained
fixing a strike and varying . In order to give conditions to prove an
existence-and-uniqueness result for the solution of the system it is here
expressed in terms of the square root of the forward implied volatility and
rewritten in an Hilbert space setting. The existence and the uniqueness for the
(arbitrage free) evolution of the forward implied volatility, and then of the
the implied volatility, among a class of models, are proved. Specific examples
are also given.Comment: 21 page
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