Russell M. Brown

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The purpose of this note is to establish a small extension of a result of Panchenko, Päivärinta and Uhlmann [14]. These authors recently showed that we have uniqueness in the inverse conductivity problem for conductivities which are in the class C 3/2 in three dimensions and higher. This built on earlier work of one the authors, Brown [3]. In this note, we(More)
Let Ω be a domain in R n whose boundary is C 1 if n ≥ 3 or C 1,β if n = 2. We consider a magnetic Schrödinger operator L W,q in Ω and show how to recover the boundary values of the tangential component of the vector potential W from the Dirichlet to Neumann map for L W,q. We also consider a steady state heat equation with convection term ∆+2W ·∇ and recover(More)
We consider the mixed problem,      ∆u = 0 in Ω ∂u ∂ν = f N on N u = f D on D in a class of Lipschitz graph domains in two dimensions with Lipschitz constant at most 1. We suppose the Dirichlet data, f D has one derivative in L p (D) of the boundary and the Neumann data is in L p (N). We find a p 0 > 1 so that for p in an interval (1, p 0), we may find(More)
We study the boundary regularity of solutions of the mixed problem for Laplace's equation in a Lipschitz graph domain Ω whose boundary is decomposed as ∂Ω = N ∪ D, where N ∩ D = ∅. For a subclass of these domains, we show that if the Neumann data g is in L p (N) and if the Dirichlet data f is in the Sobolev space L p,1 (D), for 1 < p < 2, then the mixed(More)
Approximately 438 pb −1 of e + e − data from the OPAL detector, taken with the LEP collider running at centre-of-mass energies of 192-209 GeV, are analyzed to search for evidence of chargino pair production, e + e − → ˜ χ + 1 ˜ χ − 1 , or neutralino associated production, e + e − → ˜ χ 0 2 ˜ χ 0 1. Limits are set at the 95% confidence level on the product(More)
We consider the mixed boundary value problem, or Zaremba's problem for the Laplacian in a bounded Lipschitz domain Ω in R n , n ≥ 2. We decompose the boundary ∂Ω = D ∪ N with D and N disjoint. The boundary between D and N is assumed to be a Lipschitz surface in ∂Ω. We specify Dirichlet data on D in the Sobolev space W 1,p (D) and Neumann data in L p (N).(More)
Searches for the neutral Higgs bosons h 0 and A 0 are used to obtain limits on the Type II Two Higgs Doublet Model (2HDM(II)) with no CP–violation in the Higgs sector and no additional particles besides the five Higgs bosons. The analysis combines approximately 170 pb −1 of data collected with the OPAL detector at √ s ≈ 189 GeV with previous runs at √ s ≈ m(More)
Cross-sections and angular distributions for hadronic and lepton pair final states in e + e − collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. The results are used to measure the energy dependence of the electromagnetic coupling constant α em ,(More)