N=2 Conformal Superspace in Four Dimensions

We develop the geometry of four dimensional N=2 superspace where the entire conformal algebra of SU(2,2|2) is realized linearly in the structure group rather than just the SL(2,C) x U(2)_R subgroup of Lorentz and R-symmetries, extending to N=2 our prior result for N=1 superspace. This formulation explicitly lifts to superspace the existing methods of the N=2 superconformal tensor calculus; at the same time the geometry, when degauged to SL(2,C) x U(2)_R, reproduces the existing formulation of N=2 conformal supergravity constructed by Howe.Comment: 43 pages; v2 references added, acknowledgments update

V,W and X in Technicolour Models

Light techni-fermions and pseudo Goldstone bosons that contribute to the electroweak radiative correction parameters V,W and X may relax the constraints on technicolour models from the experimental values of the parameters S and T. Order of magnitude estimates of the contributions to V,W and X from light techni-leptons are made when the the techni-neutrino has a small Dirac mass or a large Majorana mass. The contributions to V,W and X from pseudo Goldstone bosons are calculated in a gauged chiral Lagrangian. Estimates of V,W and X in one family technicolour models suggest that the upper bounds on S and T should be relaxed by between 0.1 and 1 depending upon the precise particle spectrum.Comment: 19 pages + 2 pages of ps figs, SWAT/1

4D, N = 1 Supersymmetry Genomics (I)

Presented in this paper the nature of the supersymmetrical representation theory behind 4D, N = 1 theories, as described by component fields, is investigated using the tools of Adinkras and Garden Algebras. A survey of familiar matter multiplets using these techniques reveals they are described by two fundamental valise Adinkras that are given the names of the cis-Valise (c-V) and the trans-Valise (t-V). A conjecture is made that all off-shell 4D, N = 1 component descriptions of supermultiplets are associated with two integers - the numbers of c-V and t-V Adinkras that occur in the representation.Comment: 53 pages, 19 figures, Report-II of SSTPRS 2008 Added another chapter for clarificatio

Random lattice superstrings

We propose some new simplifying ingredients for Feynman diagrams that seem necessary for random lattice formulations of superstrings. In particular, half the fermionic variables appear only in particle loops (similarly to loop momenta), reducing the supersymmetry of the constituents of the Type IIB superstring to N=1, as expected from their interpretation in the 1/N expansion as super Yang-Mills.Comment: Section 5 which describes contributions of the string measure adde

Constrained superpotentials in harmonic gauge theories with 8 supercharges

We consider D-dimensional supersymmetric gauge theories with 8 supercharges (D<6,$~\mathcal{N}=8$) in the framework of harmonic superspaces. The effective Abelian low-energy action for D=5 contains the free and Chern-Simons terms. Effective $\mathcal{N}=8$ superfield actions for D<4 can be written in terms of the superpotentials satisfying the superfield constraints and (6-D)-dimensional Laplace equations. The role of alternative harmonic structures is discussed.Comment: LATEX file, 9 pages, version published in Teor. Mat. Fi

Cosmological Supergravity from a Massive Superparticle and Super Cosmological Black Holes

We describe in superspace a classical theory of two dimensional $(1,1)$ dilaton supergravity with a cosmological constant, both with and without coupling to a massive superparticle. We give general exact non-trivial superspace solutions for the compensator superfield that describes the supergravity in both cases. We then use these compensator solutions to construct models of two-dimensional supersymmetric cosmological black holes.Comment: 20 pages, Late

The EGF/TGFα Receptor in Skin

In responsive cells, all known effects of epidermal growth factor (EGF), transforming growth factor a (TGFα), and related proteins are mediated through binding to a specific membrane receptor. The EGF/TGFα receptor is a single- chain glycoprotein (1186 amino acids) containing three functional domains: 1) an extracellular, glycosylated portion that binds EGF; 2) a small transmembrane portion; and 3) a cytoplasmic portion that has the intrinsic tyrosine kinase activity and multiple sites that can be phosphorylated. When EGF binds to the receptor its intrinsic tyrosine kinase is activated, resulting in increased phosphorylation of intracellular tyrosine residues both on the receptor (autophosphorylation sites) and on exogenous proteins involved in regulating cellular functions. Site-specific mutagenesis has established that the tyrosine-kinase activity of the receptor is essential for nearly all of the effects of EGF including its ability to elevate cellular calcium levels and to induce DNA synthesis. The binding of EGF and the kinase activity of the receptor are both regulated by the phosphorylation of the receptor on specific threonine/serine sites catalyzed by other protein kinases. Specific lipids such as sphingosine also can regulate kinase activity. Tyrosine-specific phosphoprotein phosphatases and perhaps proteases must be important in terminating the cellular response to EGF. In human skin, the response to EGF/TGFα is determined by the location and number of receptors and is modulated by processes affecting the binding affinity, internalization, and tyrosine-kinase activity of the receptor. Specific patterns of EGF binding and of immunoreactive receptors characterize normal growth and differentiation and these are altered during the abnormal growth and differentiation associated with diseases such as psoriasis, viral infections, neoplasms, and paraneoplastic syndromes. It is not clear if the altered patterns reflect the consequence of the disease or are the cause of the disease. As a cause, the EGF receptor may have undetected point mutations that result in internalization and degradation defects, aberrant phosphorylation, and dephosphorylation or abnormal glycosylation

Towards the Unification of Gravity and other Interactions: What has been Missed?

Faced with the persisting problem of the unification of gravity with other fundamental interactions we investigate the possibility of a new paradigm, according to which the basic space of physics is a multidimensional space ${\cal C}$ associated with matter configurations. We consider general relativity in ${\cal C}$. In spacetime, which is a 4-dimensional subspace of ${\cal C}$, we have not only the 4-dimensional gravity, but also other interactions, just as in Kaluza-Klein theories. We then consider a finite dimensional description of extended objects in terms of the center of mass, area, and volume degrees of freedom, which altogether form a 16-dimensional manifold whose tangent space at any point is Clifford algebra Cl(1,3). The latter algebra is very promising for the unification, and it provides description of fermions.Comment: 11 pages; Talk presented at "First Mediterranean Conference on Classical and Quantum Gravity", Kolymbari, Crete, Greece, 14-18 September 200