In a braneworld description of our universe, we must allow for the possibility of having dynamical branes around the time of the big bang. Some properties of such domain walls in motion are discussed here, for example the ability of negative-tension domain walls to bounce off spacetime singularities and the consequences for cosmological perturbations. In this context, we will also review a coll...

An exact solution is found describing the collision of a class of axisymmetric pp-waves. They are impulsive in character and their coordinate singularities become point curvature singularities at the boundaries of the interaction region. The solution is conformally flat. Concrete examples are given, involving an ultrarelativistic black hole against a burst of pure radiation or two colliding bea...

We study lower and upper bounds for the maximum size of a set of pairwise cyclic colliding permutations.

With this construction we show that MD5 collisions can be crafted easily in such a way that the principles underlying the trust in Public Key Infrastructure are violated. In particular we find it worrying that from one certificate alone it cannot be determined whether another, different certificate may exist with the same signature. For the second certificate the issuing Certification Authority...

We present a vortex method for the simulation of the interaction of an incompressible flow with rigid bodies. The method is based on a penalization technique where the system is considered as a single flow, subject to the Navier–Stokes equation with a penalization term that enforces continuity at the solid–fluid interface and rigid motion inside the solid. Level set functions are used to captur...

Some indication of conditions that are necessary for the formation of black holes from the collision of bubbles during a supercooled phase transition in the the early universe are explored. Two colliding bubbles can never form a black hole. Three colliding bubbles can refocus the energy in their walls to the extent that it becomes infinite. 98.80Cq, 04.60.+n, 97.60.Lf Typeset using REVTEX

Recently, Indesteege et al. [1] had described attacks against 23 and 24-step SHA-512 at SAC ’08. Their attacks are based on the differential path by Nikolić and Biryukov [2]. The reported complexities are 2 and 2 calls to the respective step reduced SHA-512 hash function. They provided colliding message pairs for 23-step SHA-512 but did not provide a colliding message pair for 24-step SHA-512. ...

Abstract The optimal solutions are most sensitive to the boundary conditions when performing topology optimization of components. In many applications the design domain of the components are subjected to unilateral contact conditions. In order to obtain relevant conceptual designs by topology optimization of such systems, the contact conditions should be included explicitly in the optimization....

We consider the problem of predicting motion vehicles in surrounding an autonomous car, for improved planning lane-based driving scenarios without inter-vehicle communication. First, we address single-vehicle estimation by designing a filtering scheme based on Interacting Multiple Model Kalman Filter equipped with novel intention-based models. Second, augment proposed optimization-based project...

Pulses of 100-fsec duration are obtained by synchronous pumping of a colliding-pulse ring dye laser with a mode-locked Ar(+)-ion laser. Stable operation of the synchronously pumped colliding-pulse mode-locked laser over hours was obtained by a suitable choice of the distance between the gain and the absorber in combination with an appropriate pump-pulse sequence.