2023 - Birkhäuser | Acta Scientiarum Mathematicarum
Tópico(s): Fuzzy and Soft Set Theory
2008 - Birkhäuser | Acta Scientiarum Mathematicarum
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Tópico(s): Philosophy, Science, and History
1951 - Cambridge University Press | Journal of Symbolic Logic
Tópico(s): Advanced Banach Space Theory
2002 - Birkhäuser | Acta Scientiarum Mathematicarum
Michael Kaltenbäck, Harald Woracek,
The spectral theory of a two-dimensional canonical (or ‘Hamiltonian’) system is closely related with two notions, depending whether Weyl’s limit circle or limit point case prevails. Namely, with its monodromy matrix or its Weyl coefficient, respectively. A Fourier transform exists which relates the differential operator induced by the canonical system to the operator of multiplication by the independent variable in a reproducing kernel space of entire 2-vector valued functions or in a weighted L2- ...
Tópico(s): Matrix Theory and Algorithms
2011 - Birkhäuser | Acta Scientiarum Mathematicarum
A. E. Frazho, S. ter Horst, M. A. Kaashoek,
A new description is given of all solutions to the relaxed commutant lifting problem. The method of proof is also different from earlier ones, and uses only an operator-valued version of a classical lemma on harmonic majorants. AMS Subject Classification (2000): Primary 47A20, 47A57; Secondary 31A05, 47A56.
Tópico(s): Algebraic and Geometric Analysis
2006 - Birkhäuser | Acta Scientiarum Mathematicarum
Recently, sufficent conditions for the Hp boundedness of the one-dimensional Hausdorff operator were given by Liflyand and Miyachi. In this paper, we obtain new sufficent conditions for the Hp boundedness of the one-dimensional Hausdorff operator. The results of Liflyand and Miyachi and the results of this paper are mutually independent. More importantly, our method in the proof allows us to study the high dimensional Hausdorff operator and fractional Hausdorff operator. We then obtain Hp(ℝn) → Lq( ...
Tópico(s): Analytic and geometric function theory
2012 - Birkhäuser | Acta Scientiarum Mathematicarum
Tópico(s): Algebraic and Geometric Analysis
2000 - Birkhäuser | Acta Scientiarum Mathematicarum
Zoltán Sebestyén, Zsigmond Tarcsay,
Tópico(s): Mathematical Analysis and Transform Methods
2014 - Birkhäuser | Acta Scientiarum Mathematicarum
C. J. K. Batty, Markus Haase, Junaid Mubeen,
In this article we construct a holomorphic functional calculus for operators of half-plane type and show how key facts of semigroup theory (Hille-Yosida and Gomilko-Shi-Feng generation theorems, Trotter-Kato apprximation theorem, Euler approximation formula, Gearhart-Prüss theorem) can be elegantly obtained in this framework. Then we discuss the notions of bounded H∞-calculus and m-bounded calculus on half-planes and their relation to weak bounded variation conditions over vertical lines for powers ...
Tópico(s): Spectral Theory in Mathematical Physics
2013 - Birkhäuser | Acta Scientiarum Mathematicarum
Let $$\overrightarrow{H}$$ and $$\overrightarrow{K}$$ be finite composition series of a group G. The intersections Hi ∩ Kj of their members form a lattice CSL( $$\overrightarrow{H}$$ , $$\overrightarrow{K}$$ ) under set inclusion. Improving the Jordan-Hölder theorem, G. Grätzer, J. B. Nation and the present authors have recently shown that $$\overrightarrow{H}$$ and $$\overrightarrow{K}$$ determine a unique permutation π such that, for all i, the i-th factor of $$\overrightarrow{H}$$ is “down-and-up projective”to the π(i)- ...
Tópico(s): Rough Sets and Fuzzy Logic
2013 - Birkhäuser | Acta Scientiarum Mathematicarum
Joseph A. Ball, Vladimir Bolotnikov,
The Sz.-Nagy-Foias model theory for C·0 contraction operators combined with the Beurling-Lax theorem establishes a correspondence between any two of four kinds of objects: shift-invariant subspaces, operatorvalued inner functions, conservative discrete-time input/state/output linear systems, and C·0 Hilbert-space contraction operators. We discuss an analogue of all these ideas in the context of weighted Hardy spaces over the unit disk and an associated class of hypercontraction operators.
Tópico(s): Spectral Theory in Mathematical Physics
2013 - Birkhäuser | Acta Scientiarum Mathematicarum
Tópico(s): Geometric and Algebraic Topology
2001 - Birkhäuser | Acta Scientiarum Mathematicarum
A planar semimodular lattice is slim if it does not contain M 3 as a sublattice.An SPS lattice is a slim, planar, semimodular lattice.Congruence lattices of SPS lattices satisfy a number of properties.It was conjectured that these properties characterize them.A recent result of Gábor Czédli proves that there is an eight element (planar) distributive lattice having all these properties that cannot be represented as the congruence lattice of an SPS lattice.We provide a new proof.
Tópico(s): semigroups and automata theory
2015 - Birkhäuser | Acta Scientiarum Mathematicarum
In an earlier paper, to describe how a congruence spreads from a prime interval to another in a finite lattice, I introduced the concept of prime-perspectivity and its transitive extension, prime-projectivity and proved the Prime-projectivity Lemma. In this paper, I specialize the Prime-projectivity Lemma to slim, planar, semimodular lattices to obtain the Swing Lemma, a very powerful description of the congruence generated by a prime interval in this special class of lattices.
Tópico(s): Fuzzy and Soft Set Theory
2015 - Birkhäuser | Acta Scientiarum Mathematicarum
Michael Lin, David Shoikhet, Laurain Suciu,
Let T be a bounded linear operator on a Banach space $$\mathcal{X}$$ In this paper we study uniform Cesàro ergodicity when T is not necessarily powerbounded, and relate it to the uniform convergence of the Abel averages. When $$\mathcal{X}$$ is over the complex field, we show that uniform Abel ergodicity is equivalent to the uniform convergence of the powers of all (one of) the Abel averages Aα α ∈ (0, 1). This is equivalent to uniform Cesàro ergodicity of T when ∥Tn∥/n → 0. For positive operators on real or ...
Tópico(s): Advanced Topology and Set Theory
2015 - Birkhäuser | Acta Scientiarum Mathematicarum
Tópico(s): Quantum Information and Cryptography
2015 - Birkhäuser | Acta Scientiarum Mathematicarum
John E. McCarthy, J. E. Pascoe,
The Julia quotient measures the ratio of the distance of a function value from the boundary to the distance from the boundary.The Julia-Carathéodory theorem on the bidisk states that if the Julia quotient is bounded along some sequence of nontangential approach to some point in the torus, the function must have directional derivatives in all directions pointing into the bidisk.The directional derivative, however, need not be a linear function of the direction in that case.In this note, we show that ...
Tópico(s): Mathematics and Applications
2017 - Birkhäuser | Acta Scientiarum Mathematicarum
We survey the most recent results on extension of isometries between special subsets of the unit spheres of C * -algebras, von Neumann algebras, trace class operators, preduals of von Neumann algebras, and p-Schattenvon Neumann spaces, with special interest on Tingley's problem.
Tópico(s): Holomorphic and Operator Theory
2018 - Birkhäuser | Acta Scientiarum Mathematicarum
We provide an order-theoretic characterization of algebraic orthogonality among positive elements of a general C * -algebra by proving a statement conjectured in [12].Generalizing this idea, we describe absolutely ordered p-normed spaces, for 1 ≤ p ≤ ∞ which present a model for "non-commutative vector lattices".Thid notion includes order theoretic orthogonality.We generalize algebraic orthogonality by introducing the notion of absolute compatibility among positive elements in absolute order unit spaces and ...
Tópico(s): Advanced Topics in Algebra
2018 - Birkhäuser | Acta Scientiarum Mathematicarum
Jung-Hui Liu, Chun-Yen Chou, Ching-Jou Liao, Ngai‐Ching Wong,
Tópico(s): Holomorphic and Operator Theory
2018 - Birkhäuser | Acta Scientiarum Mathematicarum
Let D be a finite distributive lattice with n join-irreducible elements. In Part III, we proved that D can be represented as the congruence lattice of a special type of planar semimodular lattices of O(n3) elements, we called rectangular. In this paper, we show that this result is best possible. Let D be a finite distributive lattice whose order of join-irreducible elements is a balanced bi-partite order on n elements. Then any rectangular lattice L whose congruence lattice is isomorphic to D has ...
Tópico(s): Advanced Algebra and Logic
2010 - Birkhäuser | Acta Scientiarum Mathematicarum
The spaces Δc0(p), Δc(p) and Δℓ∞(p) were defined by Ahmad and Mursaleen [1]. In [2], Altay and Polat also defined the sequence spaces e 0 r , e c r (Δ) and e ∞ r (Δ), and determined the absolute Köthe-Toeplitz duals of these spaces. The main purpose of this work is to introduce some new paranormed sequence spaces defined by Euler and difference operators and to compute their α-, β-, γ-duals. Also some of the matrix transformations has been characterized.
Tópico(s): Advanced Harmonic Analysis Research
2010 - Birkhäuser | Acta Scientiarum Mathematicarum
In this paper we consider the notion of n-isometry on a Banach space. We determine the existence of non-isometric 2-isometries for the classes of weighted shifts and composition operators on ℓp spaces. We also address similar questions for weighted composition operators acting on the space of scalar valued continuous functions, defined on a compact Hausdorff topological space.
Tópico(s): Advanced Operator Algebra Research
2010 - Birkhäuser | Acta Scientiarum Mathematicarum
The idea of statistical convergence was introduced in [1] and [17] and since then several generalizations and applications of this concept have been investigated by various authors. Recently Karakus [7] and Gürdal and S. Pehlivan [6] studied statistical convergence in probabilistic normed space and 2-Banach space, respectively. In this paper we propose to study statistical convergence in random 2-normed space which seems to be a quite new and interesting idea.
Tópico(s): Mathematical Approximation and Integration
2010 - Birkhäuser | Acta Scientiarum Mathematicarum
Michael Kaltenbäck, Harald Woracek,
In the theory of two-dimensional canonical (also called 'Hamiltonian') systems, the notion of the Titchmarsh-Weyl coefficient associated to a Hamiltonian function plays a vital role. A cornerstone in the spectral theory of canonical systems is the Inverse Spectral Theorem due to Louis de Branges which states that the Hamiltonian function of a given system is (up to changes of scale) fully determined by its Titchmarsh-Weyl coefficient. Much (but not all) of this theory can be viewed and explained using ...
Tópico(s): advanced mathematical theories
2010 - Birkhäuser | Acta Scientiarum Mathematicarum
Isabelle Chalendar, Emmanuel Fricain, Mehmet Gürdal, M. T. Karaev,
We answer a question raised by Nordgren and Rosenthal about the Schatten-von Neumann class membership of operators in standard reproducing kernel Hilbert spaces in terms of their Berezin symbols.
Tópico(s): Mathematical Analysis and Transform Methods
2012 - Birkhäuser | Acta Scientiarum Mathematicarum
Tópico(s): Advanced Topics in Algebra
2004 - Birkhäuser | Acta Scientiarum Mathematicarum
all commutative varieties and of all overcommutative ones.
Tópico(s): Rough Sets and Fuzzy Logic
2015 - Birkhäuser | Acta Scientiarum Mathematicarum
Tópico(s): Fuzzy and Soft Set Theory
2016 - Birkhäuser | Acta Scientiarum Mathematicarum