Generalized Gauge Field Approach To Lightlike Branes

We propose a general action describing the dynamics of lightlike (LL) p-branes in any odd (p+1) world-volume dimensions. Next, we consider self-consistent coupling of \textsl{LL}-membranes (p=2) to D=4 Einstein-Maxwell system plus a D=4 three-index antisymmetric tensor gauge field. The LL-brane serves as a material and charge source for gravity and electromagnetism and, furthermore, it produces a dynamical space-varying cosmological constant. We present static spherically-symmetric solutions where the space-time consists of two regions with different black-hole-type geometries and different values for dynamically generated cosmological constant, separated by the LL-brane which "straddles" their common event horizon.