We give an elementary introduction to the theory of supermembranes. DEDICATED TO THE MEMORY OF ABDUS SALAM Based on lectures given at the T. A. S. I. Summer School, University of Colorado, Boulder, June 1996; the Topical Meeting, Imperial College, London, July 1996 and the 26th British Universities Summer School in Theoretical Elementary Particle Physics, University of Swansea, September 1996. ...

The structure of spacetime at the Planck scale may lead to a breakdown of Lorentz invariance at high energies in the form of non-linear dispersion relations for fundamental particles. We show that observations of synchrotron emission from the Crab nebula constrain the energy scale EQG of subluminal Lorentz violation in the electron dispersion relation at order O(E/EQG) to EQG > 4.5×10 27 GeV. T...

In this paper, we describe two different learning tasks for relational structures. When learning a classifier for structures, the relational structures in the training sets are classified as a whole. Contrarily, when learning a context dependent classifier for elementary objects, the elementary objects of the relational structures in the training set are classified. We investigate the question ...

The seminal paper by Ya. B. Zeldovich (Soviet Physics Uspekhi 11, 381– 393, 1968) is reprinted here, together with an editorial comment on its lasting scientific relevance, and a biography of the author.

Over the last few years it has become increasingly clear that low energy, but high precision experiments provide a powerful and complementary window to physics beyond the Standard Model. In this note we illuminate this by using minicharged particles as an example. We argue that minicharged particles arise naturally in extensions of the Standard Model. Compatibility with charge quantization argu...

There is almost universal agreement among cosmologists that most of the matter in the Universe is dark, and there are very good reasons to believe that most of this dark matter must be nonbaryonic. The two leading candidates for this dark matter are axions and weakly-interacting massive particles (WIMPs), such as the neutralino in supersymmetric extensions of the standard model. I discuss the a...

An ever-increasing body of evidence suggests that weakly interacting massive particles (WIMPs) constitute the bulk of the matter in the Universe. We illustrate how experimental data, dimensional analysis and Standard Model particle physics are sufficient to evaluate and compare the potential of detectors searching for such particles either directly (e.g. by their scattering in germanium detecto...

In this paper I examine and question Marc Lange’s account of laws, and his claim that the law delineating the range of natural kinds of fundamental particle has a lesser grade of necessity that the laws connecting the fundamental properties of those kinds with their derived properties.

We have determined theoretically the rest mass of the muon neutrino at 50 milli-eV and the rest mass of the electron neutrino at 5 meV, as well as , to 1% accuracy, the ratio of the masses of the stable elementary particles which decay by weak decays. We assume that the particles of the neutrino branch consist of a cubic, isotropic nuclear lattice, held together by the weak nuclear force. The e...

The theory of symmetry breaking in presence of gauge fields is presented, following the historical track. Particular emphasis is placed upon the underlying concepts. Invited talks presented at the 2001 Corfu Summer Institute on Elementary Particle Physics 2 E-mail : [email protected]