Newton potential for DGP brane-world scenario is examined when the extra dimension is semi-infinite. The final form of the potential involves a self-adjoint extension parameter α, which plays a role of an additional mass (or distance) scale. The striking feature of Newton potential in this setup is that the potential behaves as seven-dimensional in long range when α is non-zero. For small α there is an intermediate range where the potential is five-dimensional. Five-dimensional Newton constant decreases with increase of α from zero. In the short range the four-dimensional behavior is recovered. The physical implication of this result is discussed in the context of the accelerating behavior of universe.

We make hamiltonian analyses of the new set of dual bosonic p-brane (in-cluding string) actions which contain high non-linearity. The di

Siegel's action is generalized to the D=2(p+1)-dimensional space-time (p even). The investigation of self-duality of chiral p-forms is extended to the momentum frame, using Siegel's action of chiral bosons in two space-time dimensions and its generalization in higher dimensions as examples. The whole procedure of the investigation is realized in the momentum space that relates to configuration space through the Fourier transformation of fields. These actions correspond to non-local Lagrangians in the momentum frame. Their selfduality with respect to dualization of chiral fields is uncovered. The relationship between two self-dual tensors in momentum space, whose form appears similar in configuration space, plays an important role in the calculation, that is, its application realizes the algebraic solution of an integral equation.

A Siegel-type chiral p-form action is proposed in D=2(p+1) spacetime dimensions. The approach we adopt is to realize the symmetric second-rank Lagrange-multiplier field, introduced in Siegel's action, in terms of a normalized multiplication of two (q+1)- form fields with q indices of each field contracted in the even p case, or of two pairs of (q+1)- form fields with q indices of each pair of fields contracted in the odd p case, where the (q+1)- form fields are of external derivatives of one auxiliary q-form field for the former, or of a pair of auxiliary q-form fields for the latter. Using this action, it is straightforward to deduce the recently constructed PST action for q equal to zero. It is found that the Siegel-type chiral p-form action with a fixed p (even or odd) is doubly self-dual in D=2(p+1) spacetime dimensions when the auxiliary field(s) is/are also chosen to be of p-form. This result includes PST's as a special case where only the chiral 0-form action is doubly self-dual in D=2 dimensions.  2001 Elsevier Science B.V. All rights reserved.

We give general intersecting brane solutions without assuming any restriction on the metric in supergravity coupled to a dilaton and antisymmetric tensor fields in arbitrary dimensions D. The result is a general class of intersecting brane solutions which interpolate the non-extreme solutions of type 1 and 2. We also discuss the relation of our solutions to the known single brane solution.