On the world-volume of an M -theory five-brane propagates a two-form with selfdual field strength. As this field is non-Lagrangian, there is no obvious framework for determining its partition function. An analogous problem exists in Type IIB superstring theory for the self-dual five-form. The resolution of these problems and definition of the partition function is explained. A more complete ana...

Freed, Harvey, Minasian and Moore have proposed a mechanism to cancel the gravitational anomaly of the M-theory fivebrane coming from diffeomorphisms acting on the normal bundle. This procedure is based on a modification of the conventional M-theory Chern-Simons term. We compactify this space-time interaction to the ten-dimensional type IIA theory. We then analyze the relation to the anomaly ca...

In the context of conventional quantum field theory, we present a general Lorentz-violating extension of the minimal SU(3) × SU(2)× U(1) standard model including CPT-even and CPTodd terms. It can be viewed as the low-energy limit of a physically relevant fundamental theory with Lorentz-covariant dynamics in which spontaneous Lorentz violation occurs. The extension has gauge invariance, energy-m...

Multiple connected devices sharing common wireless resources might create interference if they access the channel simultaneously. Medium access control (MAC) protocols generally regulate the access of the devices to the shared channel to limit signal interference. In particular, irregular repetition slotted ALOHA (IRSA) techniques can achieve high-throughput performance when interference cancel...

We consider the convergence properties of several iterative implementations of linear multiuser receivers, under the assumption of long random spreading sequences. We nd that parallel interference cancellation diverges for systems loads of greater than 17%. Using known results from the theory of iterative solutions for linear systems, we derive optimal or near optimal relaxation parameters for ...

We consider the generation of Fayet-Iliopoulos terms at one string loop in some recently found N = 1 open string orbifolds with anomalous U(1) factors with nonvanishing trace of the charge. Low-energy field theory arguments lead one to expect a one loop quadratically divergent Fayet-Iliopoulos term. We show that a one loop Fayet-Iliopoulos term is not generated, due to a cancellation between co...

Systems of exchange-coupled spins are commonly used to model ferromagnets. The quantum correlations in such magnets are studied using tools from quantum information theory. Isotropic ferromagnets are shown to possess a universal low-temperature density matrix which precludes entanglement between spins, and the mechanism of entanglement cancellation is investigated, revealing a core of states re...

A two-dimensional string model with dynamical cancellation of folds is considered. The action of the model contains the self-intersection number which is defined for surfaces immersed into 4D targets. The two additional variables are not dynamical and live on a compact manifold. In this sense the model is a compactification of a 4D theory. The cancellation forces the string θ angle to be equal ...

We present a highly adaptive hierarchical representation of the topology of functions defined over two-manifold domains. Guided by the theory of Morse-Smale complexes, we encode dependencies between cancellations of critical points using two independent structures: a traditional mesh hierarchy to store connectivity information and a new structure called cancellation trees to encode the configur...

Tree algorithms form a well researched class of collision resolution algorithms for solving multiple access control problems. Signal interference cancellation, which allows one to recover additional information from otherwise lost collision signals, has recently been combined with tree algorithms, providing substantially higher maximum stable throughputs (MSTs), up to 0.693 (Yu and Giannakis, I...