122,102 research outputs found
Modification of Born impurity scattering near the surface of d-wave superconductors and influence of external magnetic field
We study the influence of Born impurity scattering on the zero-energy Andreev
bound states near the surface of a d-wave superconductor with and without an
externally applied magnetic field. Without an external magnetic field we show
that the effect of Born impurity scattering is stronger at the surface than in
the bulk. In the presence of an external magnetic field the splitting of the
zero-energy Andreev bound states is shown to have a nonmonotonous temperature
dependence. Born impurity scattering does not wash out the peak splitting, but
instead the peak splitting is shown to be quite robust against impurities. We
also show that a nonzero gap renormalization appears near the surface.Comment: 9 pages, 17 figures; minor changes; new figure 11; accepted for
publication in Phys. Rev.
Can we live on a D-brane? -- Effective theory on a self-gravitating D-brane --
We consider a D-brane coupled with gravity in type IIB supergravity on S^5
and derive the effective theory on the D-brane in two different ways, that is,
holographic and geometrical projection methods. We find that the effective
equations on the brane obtained by these methods coincide. The theory on the
D-brane described by the Born-Infeld action is not like Einstein-Maxwell theory
in the lower order of the gradient expansion, i.e., the Maxwell field does not
appear in the theory. Thus the careful analysis and statement for cosmology on
self-gravitating D-brane should be demanded in realistic models.Comment: 13 pages, accepted for publication in Physical Review
Integrable Generalisations of the 2-dimensional Born Infeld Equation
The Born-Infeld equation in two dimensions is generalised to higher
dimensions whilst retaining Lorentz Invariance and complete integrability. This
generalisation retains homogeneity in second derivatives of the field.Comment: 11 pages, Latex, DTP/93/3
Born-Infeld-Einstein Actions?
We present some obvious physical requirements on gravitational avatars of
non-linear electrodynamics and illustrate them with explicit determinantal
Born-Infeld-Einstein models. A related procedure, using compensating Weyl
scalars, permits us to formulate conformally invariant versions of these
systems as well.Comment: 7 page
Putting Academic Fair Use to the Test
The Fair Use Doctrine is one of the most important, complex and misunderstood elements of copyright law. It was born out of the principle that copyright law needs to balance the rights of authors and creators to reap a benefit from their creations with the public’s right to continue to develop new knowledge on the foundation of these creations. It is intended to function by allowing the use of existing creative works without the need to obtain permission or pay royalties, but only for certain purposes that have been identified as serving the public good. The complexity of the Fair Use Doctrine is that it is both very broad and quite narrow. The doctrine itself can be found at Title 17, Section 107 of the United States Code. The parties involved in a fair use case will measure and weigh many elements. However, if these parties can’t agree as to whether a use is fair, lawsuits may be filed and it becomes up to the court to decide. While no one wants to be sued, there is some benefit in that the court decisions which the four factors help to further narrow the scope of the fair use test and help subsequent users determine if fair use may apply to their proposed use
The Born-Infeld Sphaleron
We study the SU(2) electroweak model in which the standard Yang-Mills
coupling is supplemented by a Born-Infeld term. The deformation of the
sphaleron and bisphaleron solutions due to the Born-Infeld term is investigated
and new branches of solutions are exhibited. Especially, we find a new branch
of solutions connecting the Born-Infeld sphaleron to the first solution of the
Kerner-Gal'tsov series.Comment: 8 pages, 5 Postscript figures; new results on Bisphalerons added;
minor modification
D-branes in lens spaces
We realize the CFT with target a lens space SU(2)/Z_l as a simple current
construction. This allows us to compute the boundary states and the annuli
coefficients, and in particular to study the B-type branes, in purely algebraic
terms. Several issues, like the appearance of fractional branes and symmetry
breaking boundary conditions, can be addressed more directly in this approach
than in a more geometric treatment.Comment: 13 page
- …