Dirichlet spectrum for one linear form
نویسندگان
چکیده
For n ⩾ 2 $n\geqslant 2$ , we determine the Dirichlet spectrum in R $\mathbb {R}^n$ with respect to a linear form and maximum norm as entire interval [0, 1]. This natural result improves on recent work of Beresnevich et al. complements subsequent paper by authors where analogous was proved for simultaneous approximation. Various generalizations that can be obtained similar methods latter are indicated. We believe our results an important step toward resolving very open problem general system forms.
منابع مشابه
A Dirichlet Form Primer
A Dirichlet form (E , D(E)), like a Feller semigroup, is an analytic object that can be used to construct and study a certain Markov process {Xt}t≥0. Unlike the Feller semigroup approach, which uses a pointwise analysis, the Dirichlet form approach uses a quasi-sure analysis, meaning that we are permitted to ignore certain exceptional sets which are not visited by the process. This slight ambig...
متن کاملThe Dirichlet problem for higher order equations in composition form
The present paper commences the study of higher order differential equations in composition form. Specifically, we consider the equation Lu = divB∗∇(a divA∇u) = 0, where A and B are elliptic matrices with complexvalued bounded measurable coefficients and a is an accretive function. Elliptic operators of this type naturally arise, for instance, via a pull-back of the bilaplacian ∆ from a Lipschi...
متن کاملSpectrum Preserving Linear Maps Between Banach Algebras
In this paper we show that if A is a unital Banach algebra and B is a purely innite C*-algebra such that has a non-zero commutative maximal ideal and $phi:A rightarrow B$ is a unital surjective spectrum preserving linear map. Then $phi$ is a Jordan homomorphism.
متن کاملA Surgery Result for the Spectrum of the Dirichlet Laplacian
In this paper we give a method to geometrically modify an open set such that the first k eigenvalues of the Dirichlet Laplacian and its perimeter are not increasing, its measure remains constant, and both perimeter and diameter decrease below a certain threshold. The key point of the analysis relies on the properties of the shape subsolutions for the torsion energy.
متن کاملAlmost multiplicative linear functionals and approximate spectrum
We define a new type of spectrum, called δ-approximate spectrum, of an element a in a complex unital Banach algebra A and show that the δ-approximate spectrum σ_δ (a) of a is compact. The relation between the δ-approximate spectrum and the usual spectrum is investigated. Also an analogue of the classical Gleason-Kahane-Zelazko theorem is established: For each ε>0, there is δ>0 such that if ϕ is...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Bulletin of The London Mathematical Society
سال: 2023
ISSN: ['1469-2120', '0024-6093']
DOI: https://doi.org/10.1112/blms.12793