Improving Extractions of |Vcb| and the b Quark Mass from Semileptonic Inclusive B Decay

Recent advances in improving extractions of |Vcb| and m_b from spectra of semileptonic inclusive B decay are reported. Results of a general moment analysis of the lepton energy spectrum and the hadronic invariant mass spectrum are summarized. The calculation of the general O(\alpha_s) structure functions for semileptonic B decay is reported, which has allowed the calculation of the O(\alpha_s Lambda_{QCD} /m_b) terms for the hadronic invariant mass moments to be carried out. Recent theoretical advances and improvements in experimental data has allowed extractions of the CKM element |Vcb| to improve to the 2% level.Comment: 8 pages, 2 figures. Talk given at MRST2004, May 12-14, Concordia, Montrea

Projections in L1(G)L^1(G); the unimodular case

We consider the issue of describing all self-adjoint idempotents (projections) in $L^1(G)$ when $G$ is a unimodular locally compact group. The approach is to take advantage of known facts concerning subspaces of the Fourier-Stieltjes and Fourier algebras of $G$ and the topology of the dual space of $G$. We obtain an explicit description of any projection in $L^1(G)$ which happens to also lie in the coefficient space of a finite direct sum of irreducible representations. This leads to a complete description of all projections in $L^1(G)$ for $G$ belonging to a class of groups that includes $SL(2,R)$ and all almost connected nilpotent locally compact groups.Comment: 13 page

Parametrized post-Newtonian virial theorem

Using the parametrized post-Newtonian equations of hydrodynamics, we derive the tensor form of the parametrized post-Newtonian virial theorem.Comment: 10 pages, submitted to CQ

Evolution and Otitis Media: A Review, and a Model to Explain High Prevalence in Indigenous Populations

Inflammation of the middle ear (otitis media) comprises a group of disorders that are highly prevalent in childhood, and indeed are amongst the most common disorders of childhood. Otitis media is also heritable, and has effects on fecundity. This means that otitis media is subject to evolution, yet the evolutionary selection forces that may determine susceptibility to otitis media have never been adequately explored. Here I undertake a critical analysis of evolutionary forces that may determine susceptibility to middle ear inflammation. These forces include those determining function of the middle ear, those affecting host immunity, and those affecting colonization by, and pathogenicity of bacteria. I review existing mathematical evolutionary models of host-pathogen interaction and co-evolution, and apply these to develop a better understanding of the complex evolutionary landscape of middle ear infection and inflammation in humans. This includes an understanding of factors determining the transition between stable evolutionary strategies for host and bacterial pathogens. This understanding will be later applied to analysis of otitis media in indigenous populations. In the second part of this article, I apply the approach of population genetics to devise a new theory for the high prevalence of otitis media in certain indigenous populations: the Australian Aborigine, the Native American, the Inuit, and the Maori. I suggest that high prevalence in such groups may have occurred as a result of colonization of these previously isolated populations by European immigrants in the 15th and 16th Centuries. This exposed them to new strains of bacteria to which their immune system had not evolved immunity, perturbing a previously stable host- pathogen co-evolutionary state