The Experts below are selected from a list of 1146 Experts worldwide ranked by ideXlab platform

Q I Minju - One of the best experts on this subject based on the ideXlab platform.

  • the natural disposition theorem on n dimension Measurable Function
    Journal of Anhui University, 2009
    Co-Authors: Q I Minju
    Abstract:

    The definition of the entire dense spot of Lebesgue Measurable set was generalized from 1-dimension to n-dimension,so did the concept of the degree and the relative degree of the discontinuity of Function,according to the definition of the entire dense spot,the almost every point of n-dimension Lebesgue Measurable set being the entire dense spot was directly proved by Vitali cover and Lusin theorem,that n-dimension Lebesgue Measurable Function was almost everywhere equal to an almost everywhere continuous Function,which was gotten by the conception of the degree and the relative degree of the discontinuity of Function.

  • the re understanding on Lebesgue non Measurable set
    Journal of Shanghai Dianji University, 2007
    Co-Authors: Q I Minju
    Abstract:

    A Lebesgue non-Measurable set with characteristic Function that is somewhat similar to Dirchlet Function is given,according to the properties of the essentialization theorem on Lebesgue Measurable Function.

  • the re understanding on Lebesgue Measurable Function
    Journal of Shanghai Dianji University, 2007
    Co-Authors: Q I Minju
    Abstract:

    Based on that Lebesgue Measurable Function is almost everywhere equal to the almost everywhere continuous Function on ,an equivalent definition and several properties on Lebesgue Measurable Function are given,and so is the tentative plan on Lebesgue Measurable Function to enter the mathematics teaching of the engineering course.

N Nadirashvili - One of the best experts on this subject based on the ideXlab platform.

  • on the restricted mean value property for Measurable Functions
    1994
    Co-Authors: W Hansen, N Nadirashvili
    Abstract:

    Let U be a domain in ℝ d , d ≥ 1, and r > 0 a real Function on U such that B(x,r(x)):= {y ∈ ℝd: ‖x - y‖ < r(x)} ⊂ U for every x ∈ U. A Lebesgue Measurable Function f on U which is bounded by some harmonic Function h ≥ 0 on U is called r-median if $$f\left( x \right) = \int {fd{\lambda _{B\left( {x,r\left( x \right)} \right)}}} $$ for every x ∈ U (⋋ Lebesgue measure on ℝ d ⋋ B = ⋋(B) -11 B ⋋ for every ball B).

  • a converse to the mean value theorem for harmonic Functions
    Acta Mathematica, 1993
    Co-Authors: Wolfhard Hansen, N Nadirashvili
    Abstract:

    (A Lebesgue measure on Rd). The converse question to what extent this restricted mean value property implies harmonicity has a long history (we axe indebted to I. Netuka for valuable hints). Volterra [26] and Kellogg [20] noted first that a continuous Function f on the closure U of U satisfying (*) is harmonic on U. At least if U is regular there is a very elementary proof for this fact (see Burckel [7]): Let g be the difference between f and the solution of the Dirichlet problem with boundary value f . If g#0 , say a=sup g(U)> 0, choose x6{g=a} having minimal distance to the boundary. Then (*) leads to an immediate contradiction. In fact, for continuous Functions on U the question is settled for arbitrary harmonic spaces and arbitrary representing measures #x # ~ for harmonic Functions. If f is bounded on U and Borel Measurable the answer may be negative unless restrictions on the radius r(x) of the balls B ~ are imposed (Veech [23]): Let U = ] I , 1[, / (0 )=0 , f = i on ] -1 ,0[ , f= l on ]0, 1[, 0~B x for x?t0 (similarly in R d, d/>2)! There are various positive results, sometimes under restrictions on U, but always under restrictions on the Function x~-+r(x) (Feller [9], Akcoglu and Sharpe [1], Baxter [2] and [3], Heath [17], Veech [23] and [24]). For example Heath [17] showed for arbitrary U that a bounded Lebesgue Measurable Function on U having the restricted mean value property (.) is harmonic provided that , for some e>0, cd(x, CU)Lebesgue Measurable Function f on U

Shi Rui - One of the best experts on this subject based on the ideXlab platform.

  • On a class of operators in the hyperfinite $\mathrm{II}_1$ factor
    Mathematica Scandinavica, 2017
    Co-Authors: Zhu Zhangsheng, Fang Junsheng, Shi Rui
    Abstract:

    Let $R$ be the hyperfinite $\mathrm {II}_1$ factor and let $u$, $v$ be two generators of $R$ such that $u^*u=v^*v=1$ and $vu=e^{2\pi i\theta } uv$ for an irrational number $\theta$. In this paper we study the class of operators $uf(v)$, where $f$ is a bounded Lebesgue Measurable Function on the unit circle $S^1$. We calculate the spectrum and Brown spectrum of operators $uf(v)$, and study the invariant subspace problem of such operators relative to $R$. We show that under general assumptions the von Neumann algebra generated by $uf(v)$ is an irreducible subfactor of $R$ with index $n$ for some natural number $n$, and the $C^*$-algebra generated by $uf(v)$ and the identity operator is a generalized universal irrational rotation $C^*$-algebra

  • On a class of operators in the hyperfinite ${\rm II}_1$ factor
    2014
    Co-Authors: Zhu Zhangsheng, Fang Junsheng, Shi Rui
    Abstract:

    Let $R$ be the hyperfinite ${\rm II}_1$ factor and let $u,v$ be two generators of $R$ such that $u^*u=v^*v=1$ and $vu=e^{2\pi i\theta} uv$ for an irrational number $\theta$. In this paper we study the class of operators $uf(v)$, where $f$ is a bounded Lebesgue Measurable Function on the unit circle $S^1$. We calculate the spectrum and Brown spectrum of operators $uf(v)$, and study the invariant subspace problem of such operators relative to $R$. We show that under general assumptions the von Neumann algebra generated by $uf(v)$ is an irreducible subfactor of $R$ with index $n$ for some natural number $n$, and the $C^*$-algebra generated by $uf(v)$ and the identity operator is a generalized universal irrational rotation $C^*$-algebra.Comment: 20pages. arXiv admin note: text overlap with arXiv:0708.1968 by other author

Pereira F.l. - One of the best experts on this subject based on the ideXlab platform.

F.l. Pereira - One of the best experts on this subject based on the ideXlab platform.