Numerical boundaries for some classical Banach spaces

Globevnik gave the definition of boundary for a subspace . This is a subset of Ω that is a norming set for . We introduce the concept of numerical boundary. For a Banach space X, a subset BΠ(X) is a numerical boundary for a subspace if the numerical radius of f is the supremum of the modulus of all the evaluations of f at B, for every f in . We give examples of numerical boundaries for the complex spaces X=c₀, and d_*(w,1), the predual of the Lorentz sequence space d(w,1). In all these cases (if K is infinite) we show that there are closed and disjoint numerical boundaries for the space of the functions from B_X to X which are uniformly continuous and holomorphic on the open unit ball and there is no minimal closed numerical boundary. In the case of c₀, we characterize the numerical boundaries for that space of holomorphic functions.     

Robustness of the controllability for the heat equation under the influence of multiple impulses and delays

For many control systems in real life, impulses and delays are intrinsic properties that do not modify their behavior. Thus, we conjecture that under certain conditions the abrupt changes and delays as perturbations of a system, that could model a real situation, do not modify properties such as controllability. In this regard, we prove the approximate controllability of the semilinear heat equation under the influence of multiple impulses and delays, this is done by using new techniques, avoiding fixed point theorems, employed by A.E. Bashirov et al.     

Precision top-quark mass measurement in the lepton+jets topology in p p collisions at square root s=1.96 TeV

We report two measurements of the top-quark mass M(top) using the CDF II detector at the Fermilab Tevatron in a 318 pb(-1) data sample of tt events in the lepton+jets final state. One method uses an event-based likelihood technique resulting in M(top) = 173.2(-2.4)(+2.6)(stat) +/- 3.2(syst) GeV/c2 or 173.2(-4.0)(+4.1) GeV/c2. The second method reconstructs a top-quark mass in each event using the measured invariant mass of the hadronically decaying W boson to constrain the jet energy scale to obtain a value for M(top)of 173.5(-3.6)(+3.7)(stat) +/- 1.3(syst) GeV/c2 or 173.5(-3.8)(+3.9) GeV/c2 . We take the latter, which is more precise, as our result.     

Search for excited and exotic muons in the mugamma decay channel in p-p collisions at sqrt s =1.96 TeV

We search for excited and exotic muon states mu* using an integrated luminosity of 371 pb(-1) of p[over]p collision data at sqrt[s]=1.96 TeV. We search for associated production of mumu* followed by the decay mu*-->mugamma. We compare the data to model predictions as a function of the mass of the excited muon M(mu*), the compositeness energy scale Lambda, and the gauge coupling factor f. No signal above the standard model expectation is observed. We exclude 107相似文献   

Radikalische Copolymerisation von cyclischen Acetalen, die sich vom Acrolein ableiten. 2. Mitt. Alternierende Copolymerisation

Ohne Zusammenfassung     

Radikalische Copolymerisation von Vinylketonen. 1. Mitt. Copolymerisation mit Acrylnitril

Ohne Zusammenfassung     

Diffractive dijet production at sqrt[s] = 630 and 1800 GeV at the Fermilab Tevatron

We report a measurement of the diffractive structure function F(D)(jj) of the antiproton obtained from a study of dijet events produced in association with a leading antiproton in pp collisions at sqrt[s] = 630 GeV at the Fermilab Tevatron. The ratio of F(D)(jj) at sqrt[s] = 630 GeV to F(D)(jj) obtained from a similar measurement at sqrt[s] = 1800 GeV is compared with expectations from QCD factorization and other theoretical predictions. We also report a measurement of the xi ( x-Pomeron) and beta ( x of parton in Pomeron) dependence of F(D)(jj) at sqrt[s] = 1800 GeV. In the region 0.035相似文献   

Discretization and best approximation in Besov spaces

In this paper we prove a theorem about existence of best approximation in a class of spaces involving Besov spaces, via a discretization technique. It is a consequence of this theorem that rational functions and exponencial sums are proximinal subsets of B _∞,q ^a (π). It is also proved the proximinality of R _m ⁿ [a, b] in B _p,q ^a (π) for arbitrary p,q and a.     

Search for lepton flavor violating decays of a heavy neutral particle in p(-)p collisions at sqrt[s]=1.8 TeV

We report on a search for a high mass, narrow width particle that decays directly to emu, etau, or microtau. We use approximately 110 pb(-1) of data collected with the Collider Detector at Fermilab from 1992 to 1995. No evidence of lepton flavor violating decays is found. Limits are set on the production and decay of sneutrinos with R-parity violating interactions.