Search results for "OMEGA"
showing 10 items of 1174 documents
Maslov Anomaly and the Morse Index Theorem
2001
Our starting point is again the phase space integral $$\displaystyle{ \text{e}^{\text{i}\hat{\varGamma }[\tilde{M}]} =\int \mathcal{D}\chi ^{a}\,\text{e}^{\text{i}S_{\text{fl}}[\chi,\tilde{M}]} }$$ (31.1) with periodic boundary conditions χ(0) = χ(T) and $$\displaystyle{ S_{\text{fl}}[\chi,\tilde{M}] = \frac{1} {2}\int _{0}^{T}dt\,\bar{\chi }_{ a}(t)\left [ \frac{\partial } {\partial t} -\tilde{M}(t)\right ]_{\phantom{a}b}^{a}\chi ^{b}(t)\;. }$$ (31.2) Here we have indicated that Sfl and \(\hat{\varGamma }\) depend on ηcl a and A i only through \(\tilde{M}_{\phantom{a}b}^{a}\): $$\displaystyle{ \tilde{M}(t)_{\phantom{a}b}^{a} =\omega ^{ac}\partial _{ c}\partial _{b}\mathcal{H}{\bigl (\eta _…
Zu einem Satz von Isaacs �ber das Casus-Irreducibilis Ph�nomen
2000
Let \(\Omega \) be a field (of characteristic 0). A prime p is called “bose” (naughty) if \(\Omega \) contains all p-th roots of unity. In this paper the theorem is proved: Let K be an admissible subfield of \(\Omega \) (i.e. for each prime p K contains all p-th roots of unity lying in \(\Omega \)), a an algebraic element of \(\Omega /K\) which is contained in a repeated radical extension of K lying in \(\Omega \). Furthermore let the normal hull L of a over K be contained in \(\Omega \). Then all prime divisors of \(\mid L : K \mid \) are naughty (and L is a repeated radical extension of K with naughty prime exponents). This result generalises a theorem of Isaacs [1] who treats the case \(…
Product Integration for Weakly Singular Integral Equations In ℝm
1985
In this note we discuss the numerical solution of the second kind Fredholm integral equation: $$ y(t) = f(t) + \lambda \int\limits_{\Omega } {{{\psi }_{\alpha }}(|t - s|)g(t,s)y(s)ds,\;t \in \bar{\Omega },} $$ (1) Where \( \lambda \in ;\not{ \subset }\backslash \{ 0\} \) , the functions f,g are given and continuous, |.| denotes the Euclidean norm, and φα, 0 \alpha > 0} \\ {\left\{ {\begin{array}{*{20}{c}} {\ln (r),} & {j = 0} \\ {{{r}^{{ - j}}}} & {j > 0} \\ \end{array} } \right\},\alpha = m} \\ \end{array} ,} \right. $$ with Cj not depending on r. Here Ω _ is the closure of a bounded domain Ω⊂ℝm.
${\cal H}^1$ -estimates of Jacobians by subdeterminants
2002
Let $f:\Omega \rightarrow{\Bbb R}^n$ be a mapping in the Sobolev space $W^{1,n-1}_{loc}(\Omega,{\Bbb R}^n), n\geq 2$ . We assume that the cofactors of the differential matrix Df(x) belong to $L^\frac{n}{n-1}(\Omega)$ . Then, among other things, we prove that the Jacobian determinant detDf lies in the Hardy space ${\cal H}^1(\Omega)$ .
Sufficient conditions for supersolubility of finite groups
1998
Abstract In this paper sufficient conditions for the supersolubility of finite groups are given under the assumption that the maximal subgroups of Sylow subgroups of the group and the maximal subgroups of Sylow subgroups of the Fitting subgroup are well-situated in the group. That will improve earlier results of Srinivasan [7], Asaad et al. [1] and Ballester-Bolinches [2].
ON A PERMUTABILITY PROPERTY OF SUBGROUPS OF FINITE SOLUBLE GROUPS
2010
The structure and embedding of subgroups permuting with the system normalizers of a finite soluble group are studied in the paper. It is also proved that the class of all finite soluble groups in which every subnormal subgroup permutes with the Sylow subgroups is properly contained in the class of all soluble groups whose subnormal subgroups permute with the system normalizers while this latter is properly contained in the class of all supersoluble groups.
Faraday patterns in low-dimensional Bose-Einstein condensates
2004
We show that Faraday patterns can be excited in the weak confinement space of low-dimensional Bose-Einstein condensates by temporal modulation of the trap width, or equivalently of the trap frequency Omega_tight, in the tight confinement space. For slow modulation, as compared with Omega_tight, the low-dimensional dynamics of the condensate in the weak confinement space is described by a Gross-Pitaevskii equation with time modulated nonlinearity coefficient. For increasing modulation frequencies a noticeable reduction of the pattern formation threshold is observed close to 2*Omega_tight, which is related to the parametric excitation of the internal breathing mode in the tight confinement sp…
An investigation on the relationship between the occurrence of CMV DNAemia and the development of invasive aspergillosis in the allogeneic stem cell …
2013
Cytomegalovirus (CMV) infection might increase the risk of fungal superinfection in allogeneic stem cell transplant patients. The potential association between the occurrence of CMV DNAemia and the development of invasive aspergillosis in this clinical setting was investigated. The current retrospective observational study included 167 patients undergoing T cell-replete allogeneic stem cell transplantation. Virological monitoring of active CMV infection was performed by the pp65 antigenemia assay and/or by a plasma real-time PCR assay. A total of 109 out of 167 patients developed CMV DNAemia. Twenty-three patients had proven (n = 4) or probable (n = 19) invasive aspergillosis. The occurrenc…
P228 Cytomegalovirus Infection: is it a cause of flare-up in inflammatory bowel diseases?
2020
Abstract Background The presence of CMV in blood is quite common in patients with severe flares of ulcerative colitis (UC) and Crohn’s disease (CD) and seems to predict an adverse outcome. The impact of antiviral treatment on CMV in this setting (indications and drug options) is an unresolved issue. Our aim was to reassess the CMV role in patients with IBD hospitalised for severe exacerbations, analysing the relationship between CMV positivity, clinical characteristics, antiviral therapy and disease outcomes. Methods We evaluated a homogeneous cohort of 97 consecutive patients with IBD hospitalised from 2012 to 2018. Data regarding age, gender, smoke, familial predisposition, type of IBD, e…
Guaranteed Error Bounds for Conforming Approximations of a Maxwell Type Problem
2009
This paper is concerned with computable error estimates for approximations to a boundary-value problem $$\mathrm{curl}\ {\mu }^{-1}\mathrm{curl}\ u + {\kappa }^{2}u = j\quad \textrm{ in }\Omega ,$$ where μ > 0 and κ are bounded functions. We derive a posteriori error estimates valid for any conforming approximations of the considered problems. For this purpose, we apply a new approach that is based on certain transformations of the basic integral identity. The consistency of the derived a posteriori error estimates is proved and the corresponding computational strategies are discussed.