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31. Automorphisms and generalized skew derivations which are strong commutativity preserving on polynomials in prime and semiprime rings

Creator:
De Filippis, Vincenzo
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, derivace funkce, mathematics, derivatives (mathematics), generalized skew derivation, prime ring, 13, and 51
Language:
English
Description:
Let R be a prime ring of characteristic different from 2, Qr its right Martindale quotient ring and C its extended centroid. Suppose that F, G are generalized skew derivations of R with the same associated automorphism α, and p(x1, ..., xn) is a non-central polynomial over C such that \left[ {F(x),\alpha (y)} \right] = G(\left[ {x,y} \right]). for all x,y\in \left \{ p\left ( r_{1},...,r_{n} \right ):r_{1},...,r_{n}\in R\right \}. The there exist \lambda \in C such that F(x) = G(x) = λα(x) for all X\in R., Vincenzo De Filippis., and Obsahuje seznam literatury
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32. Baire classes of complex L1-preduals

Creator:
Pavel Ludvík and Jiří Spurný
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
Matematika, matematika, mathematics, complex L1-predual, extreme point, Baire function, 13, and 51
Language:
English
Description:
Let X be a complex L1-predual, non-separable in general. We investigate extendability of complex-valued bounded homogeneous Baire-α functions on the set ext B_{X*} of the extreme points of the dual unit ball B_{X*} to the whole unit ball B_{X*}. As a corollary we show that, given α \in [1, ω1), the intrinsic α-th Baire class of X can be identified with the space of bounded homogeneous Baire-α functions on the set ext B_{X*} when ext B_{X*} satisfies certain topological assumptions. The paper is intended to be a complex counterpart to the same authors’ paper: Baire classes of non-separable L1-preduals (2015). As such it generalizes former work of Lindenstrauss and Wulbert (1969), Jellett (1985), and ourselves (2014), (2015)., Pavel Ludvík, Jiří Spurný., and Obsahuje seznam literatury
Rights:
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33. Banach spaces of homogeneous polynomials without the approximation property

Creator:
Dineen, Seán and Mujica, Jorge
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, mathematics, Banach space, approximation property, linear operator, homogeneous polynomial, holomorphic function, 13, and 51
Language:
English
Description:
We present simple proofs that spaces of homogeneous polynomials on Lp[0, 1] and ℓp provide plenty of natural examples of Banach spaces without the approximation property. By giving necessary and sufficient conditions, our results bring to completion, at least for an important collection of Banach spaces, a circle of results begun in 1976 by R. Aron and M. Schottenloher (1976)., Seán Dineen, Jorge Mujica., and Obsahuje seznam literatury
Rights:
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34. Basic equations of G-almost geodesic mappings of the second type, which have the property of reciprocity

Creator:
Stanković, Mića S, Zlatanović, Milan L, and Vesić, Nenad O
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
non-symmetric affine connection, almost geodesic mapping, G-almost geodesic mapping, property of reciprocity, almost geodesic mapping of the second type, 13, and 51
Language:
English
Description:
We study G-almost geodesic mappings of the second type \mathop {{\pi _2}}\limits_\theta (e),\theta = 1,2 between non-symmetric affine connection spaces. These mappings are a generalization of the second type almost geodesic mappings defined by N. S. Sinyukov (1979). We investigate a special type of these mappings in this paper. We also consider e-structures that generate mappings of type \mathop {{\pi _2}}\limits_\theta (e),\theta = 1,2. For a mapping \mathop {{\pi _2}}\limits_\theta (e,F),\theta = 1,2 we determine the basic equations which generate them., Mića S. Stanković, Milan L. Zlatanović, Nenad O. Vesić., and Obsahuje seznam literatury
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35. Boundedness in a quasilinear parabolic-parabolic chemotaxis system with nonlinear logistic source

Creator:
Liu, Ji and Zheng, Jia-Shan
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, mathematics, boundedness, chemotaxis, nonlinear logistic source, 13, and 51
Language:
English
Description:
We study a quasilinear parabolic-parabolic chemotaxis system with nonlinear logistic source, under homogeneous Neumann boundary conditions in a smooth bounded domain. By establishing proper a priori estimates we prove that, with both the diffusion function and the chemotaxis sensitivity function being positive, the corresponding initial boundary value problem admits a unique global classical solution which is uniformly bounded. The result of this paper is a generalization of that of Cao (2014)., Ji Liu, Jia-Shan Zheng., and Obsahuje seznam literatury
Rights:
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36. Boundedness of para-product operators on spaces of homogeneous type

Creator:
Xiao, Yayuan
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, mathematics, ohraničení, boundedness, Calderón-Zygmund singular integral operator, para-product, 13, and 51
Language:
English
Description:
We obtain the boundedness of Calderón-Zygmund singular integral operators T of non-convolution type on Hardy spaces Hp(X) for 1/(1 + ε) < p < 1, where X is a space of homogeneous type in the sense of Coifman and Weiss (1971), and ε is the regularity exponent of the kernel of the singular integral operator T. Our approach relies on the discrete Littlewood-Paley-Stein theory and discrete Calderón’s identity. The crucial feature of our proof is to avoid atomic decomposition and molecular theory in contrast to what was used in the literature., Yayuan Xiao., and Obsahuje bibliografii
Rights:
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37. Bounds for the number of meeting edges in graph partitioning

Creator:
Zeng, Qinghou and Hou, Jianfeng
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, mathematics, graph, weighted hypergraph, partition, judicious partition, 13, and 51
Language:
English
Description:
Let $G$ be a weighted hypergraph with edges of size at most 2. Bollobás and Scott conjectured that $G$ admits a bipartition such that each vertex class meets edges of total weight at least $(w_1-\Delta_1)/2+2w_2/3$, where $w_i$ is the total weight of edges of size $i$ and $\Delta_1$ is the maximum weight of an edge of size 1. In this paper, for positive integer weighted hypergraph $G$ (i.e., multi-hypergraph), we show that there exists a bipartition of $G$ such that each vertex class meets edges of total weight at least $(w_0-1)/6+(w_1-\Delta_1)/3+2w_2/3$, where $w_0$ is the number of edges of size 1. This generalizes a result of Haslegrave. Based on this result, we show that every graph with $m$ edges, except for $K_2$ and $K_{1,3}$, admits a tripartition such that each vertex class meets at least $\lceil{2m}/5\rceil$ edges, which establishes a special case of a more general conjecture of Bollobás and Scott., Qinghou Zeng, Jianfeng Hou., and Obsahuje bibliografické odkazy
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38. C*-algebras have a quantitative version of Pełczyński's property (V)

Creator:
Krulišová, Hana
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, mathematics, Pełczyński's property (V), $C^*$-algebra, Grothendieck property, 13, and 51
Language:
English
Description:
A Banach space $X$ has Pełczyński's property (V) if for every Banach space $Y$ every unconditionally converging operator $T\colon X\to Y$ is weakly compact. H. Pfitzner proved that $C^*$-algebras have Pełczyński's property (V). In the preprint (Krulišová, (2015)) the author explores possible quantifications of the property (V) and shows that $C(K)$ spaces for a compact Hausdorff space $K$ enjoy a quantitative version of the property (V). In this paper we generalize this result by quantifying Pfitzner's theorem. Moreover, we prove that in dual Banach spaces a quantitative version of the property (V) implies a quantitative version of the Grothendieck property., Hana Krulišová., and Obsahuje bibliografii
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39. Cartan-Eilenberg projective, injective and flat complexes

Creator:
Zhai, Xiaorui and Zhang, Chunxia
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, komplexy (matematika), mathematics, complexes, Cartan-Eilenberg projective complex, Cartan-Eilenberg injective complex, Cartan-Eilenberg flat complex, 13, and 51
Language:
English
Description:
Let R be an associative ring with identity and F a class of R-modules. In this article: we first give a detailed treatment of Cartan-Eilenberg F complexes and extend the basic properties of the class F to the class CE(F). Secondly, we study and give some equivalent characterizations of Cartan-Eilenberg projective, injective and flat complexes which are similar to projective, injective and flat modules, respectively. As applications, we characterize some classical rings in terms of these complexes, including coherent, Noetherian, von Neumann regular rings, QF rings, semisimple rings, hereditary rings and perfect rings., Xiaorui Zhai, Chunxia Zhang., and Obsahuje seznam literatury
Rights:
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40. Certain decompositions of matrices over Abelian rings

Creator:
Ashrafi, Nahid, Sheibani, Marjan, and Huanyin Chen
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
matematika, mathematics, weakly nil clean ring, idempotent element, nilpotent element, nil clean ring, 13, and 51
Language:
English
Description:
A ring R is (weakly) nil clean provided that every element in R is the sum of a (weak) idempotent and a nilpotent. We characterize nil and weakly nil matrix rings over abelian rings. Let R be abelian, and let n 2 N. We prove that Mn(R) is nil clean if and only if R/J(R) is Boolean and Mn(J(R)) is nil. Furthermore, we prove that R is weakly nil clean if and only if R is periodic; R/J(R) is Z3, B or Z3 B where B is a Boolean ring, and that Mn(R) is weakly nil clean if and only if Mn(R) is nil clean for all n > 2., Nahid Ashrafi, Marjan Sheibani, Huanyin Chen., and Seznam literatury
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