<Emphasis Type=\"Italic\">p</Emphasis>-Adic valuation of the Morgan–Voyce sequence and <Emphasis Type=\"Italic\">p</Emphasis>-regularity

We characterize the p-adic valuation of the Morgan–Voyce sequence and its companion sequence. Further, we show that the p-adic valuation of the Morgan–Voyce sequence is a p-regular sequence and we determine its rank explicitly.     

On Douglas general (<Emphasis Type=\"Italic\">α</Emphasis>, <Emphasis Type=\"Italic\">β</Emphasis>)-metrics

Douglas metrics are metrics with vanishing Douglas curvature which is an important projective invariant in Finsler geometry. To find more Douglas metrics, in this paper we consider a class of Finsler metrics called general (α, β)-metrics, which are defined by a Riemannian metric (alpha = sqrt {{a_{ij}}left( x right){y^i}{y^j}} ) and a 1-form β = b _i (x)y ⁱ . We obtain the differential equations that characterizes these metrics with vanishing Douglas curvature. By solving the equivalent PDEs, the metrics in this class are totally determined. Then many new Douglas metrics are constructed.     

Free completely <Emphasis Type=\"Italic\">J</Emphasis><Superscript>(<Emphasis Type=\"Italic\">ℓ</Emphasis>)</Superscript>-simple Semigroups

A semigroup is called completely J^(ι)-simple if it is isomorphic to some Rees matrix semigroup over a left cancellative monoid and each entry of whose sandwich matrix is in the group of units of the left cancellative monoid. It is proved that completely J^(ι)-simple semigroups form a quasivarity. Moreover, the construction of free completely J^(ι)-simple semigroups is given. It is found that a free completely J^(ι)-simple semigroup is just a free completely J ^*-simple semigroup and also a full subsemigroup of some completely simple semigroups.     

On the Gosper’s <Emphasis Type=\"Italic\">q</Emphasis>-constant Π<Subscript><Emphasis Type=\"Italic\">q</Emphasis></Subscript>

Gosper introduced the functions sin_qz and cos_qz as q-analogues for the trigonometric functions sin z and cos z respectively. He stated a variety of identities involving these two q-trigonometric functions along with certain constants denoted by ({Pi _{{q^n}}}) (n ∈ N). Gosper noticed that all his formulas on these constants have more than two of the ({Pi _{{q^n}}}). So, it is natural to raise the question of establishing identities involving only two of the ({Pi _{{q^n}}}). In this paper, our main goal is to give examples of such formulas in only two ({Pi _{{q^n}}}).     

<Emphasis Type="BoldItalic">π</Emphasis>-forms of Brauer’s <Emphasis Type="BoldItalic">k</Emphasis>(<Emphasis Type="BoldItalic">B</Emphasis>)—conjecture and Olsson’s Conjecture

Our main purpose of this paper is to give π-block forms of Brauer’s k(B) −conjecture and Olsson’s conjecture for finite π −separable groups.     

Optimum super-simple mixed covering arrays of type <Emphasis Type=\"Italic\">a</Emphasis><Superscript>1</Superscript><Emphasis Type=\"Italic\">b</Emphasis><Superscript><Emphasis Type=\"Italic\">k</Emphasis>−1</Superscript>

A mixed covering array (MCA) of type (_v 1, v ₂,..., v _k ), denoted by MCA_λ (N; t, k, (v ₁, v ₂,..., v _k )), is an N × k array with entries in the i-th column from a set _{V i} of v _i symbols and has the property that each N × t sub-array covers all the t-tuples at least λ times, where 1 ≤ i ≤ k. An MCA _λ (N; t, k, (_v 1, v ₂,..., v _k )) is said to be super-simple, if each of its N × (t + 1) sub-arrays contains each (t + 1)-tuple at most once. Recently, it was proved by Tang, Yin and the author that an optimum super-simple MCA of type (a, b, b,..., b) is equivalent to a mixed detecting array (DTA) of type (a, b, b,..., b) with optimum size. Such DTAs can be used to generate test suites to identify and determine the interaction faults between the factors in a component-based system. In this paper, some combinatorial constructions of optimum super-simple MCAs of type (a, b, b,..., b) are provided. By employing these constructions, some optimum super-simple MCAs are then obtained. In particular, the spectrum across which optimum super-simple MCA₂(2b ²; 2, 4, (a, b, b, b))′s exist, is completely determined, where 2 ≤ a ≤ b.     

Convergence Theorems for ℓ<Subscript><Emphasis Type="Italic">p</Emphasis></Subscript>-Norm Minimizers with Respect to <Emphasis Type="Italic">p</Emphasis>

Let C be a fixed compact convex subset of and let x_p be the unique minimal _p-norm element in C for any . In this paper, we study the convergence of x_p as p or , respectively. We characterize also the limit point as the minimal element of C with respect to the lexical minimax order relation or the lexical minitotal order relation, respectively.Communicated by D. G. LuenbergerThe author thanks Professor H. Komiya for valuable advice and an anonymous referee for kind comments.     

Jackson-type inequalities and exact values of widths of classes of functions in the spaces <Emphasis Type="Italic">S</Emphasis><Superscript><Emphasis Type="Italic">p</Emphasis></Superscript>, 1 ≤ <Emphasis Type="Italic">p</Emphasis> < ∞

In the spaces S^p, 1 p < , introduced by Stepanets, we obtain exact Jackson-type inequalities and compute the exact values of widths of classes of functions determined by averaged moduli of continuity of order m.Translated from Ukrainskyi Matematychnyi Zhurnal, Vol. 56, No. 5, pp. 595–605, May, 2004.     

On the regularity of scalar <Emphasis Type="Italic">p</Emphasis>-Harmonic functions in <Emphasis Type="Italic">n</Emphasis> dimensions with 2 ≤ <Emphasis Type="Italic">p</Emphasis> < <Emphasis Type="Italic">n</Emphasis>

Using Tilli’s technique [Cal Var 25(3):395–401, 2006], we shall give a new proof of the regularity of the local minima of the functional

$J\left( u\right) =\int\limits_{\Omega } \left\vert \partial u\right\vert^{p}\,dx$

with Ω a domain of class C ^{0, 1} in \({\mathbb{R}^{n}}\) and 2 ≤ p < n.

     

Flag-transitive point-primitive automorphism groups of non-symmetric 2-(<Emphasis Type=\"Italic\">v</Emphasis>, <Emphasis Type=\"Italic\">k</Emphasis>, 3) designs

In this paper, we show that if ({mathcal {D}}) is a non-trivial non-symmetric 2-(v, k, 3) design admitting a flag-transitive point-primitive automorphism group G, then G must be an affine or almost simple group.     

The James constant for the <Emphasis Type=\"Italic\">l</Emphasis><Subscript>3</Subscript> − <Emphasis Type=\"Italic\">l</Emphasis><Subscript>1</Subscript> space

In this note, the exact value of the James constant for the l₃-l₁ space is obtained, J(l₃-l₁)=1.5573…. This result improves the known inequality, J(l₃-l₁)≤4/³√10, which was given by Dhompongsa, Piraisangjun and Saejung.     

Weak-Polynomial Convergence on Spaces ℓ<Subscript><Emphasis Type="Italic">p</Emphasis></Subscript> and <Emphasis Type="Italic">L</Emphasis><Subscript><Emphasis Type="Italic">p</Emphasis></Subscript>

This paper is concerned with the study of the set P ^-1(0), when P varies over all orthogonally additive polynomials on _p and L _p spaces. We apply our results to obtain characterizations of the weak-polynomial topologies associated to this class of polynomials.     

<Emphasis Type="Italic">p</Emphasis>-Adic Brownian motion over ℚ<Subscript><Emphasis Type="Italic">p</Emphasis></Subscript>

In this paper, we generalize the result of Bikulov and Volovich (1997) and construct a p-adic Brownian motion over ℚ _p . First, we construct directly a p-adic white noise over ℚ _p by using a specific complete orthonormal system of (ℚ _p ). A p-adic Brownian motion over ℚ _p is then constructed by the Paley-Wiener method. Finally, we introduce a p-adic random walk and prove a theorem on the approximation of a p-adic Brownian motion by a p-adic random walk.     

The <Emphasis Type=\"Italic\">α</Emphasis>-comparison Property and Finite Nuclear Dimension of Generalized Inductive Limits for <Emphasis Type=\"Italic\">C</Emphasis>*-algebras

The paper is devoted to the study of generalized inductive limit of C*-algebras with coherent maps being completely positive contractions of order zero: the nuclear dimension of generalized inductive limit of C*-algebras with finite nuclear dimension is finite; the generalized inductive limits of C*-algebras with the α-comparison property also have the α-comparison property.     

An error in a proof in <Emphasis Type="BoldItalic">Boolean Algebras</Emphasis><Emphasis Type="BoldItalic">with Operators,Part I</Emphasis>

An error in a proof of a correct theorem in the classic paper, Boolean Algebras with Operators, Part I, by Jónsson and Tarski is discussed.     

The smooth structure set of <Emphasis Type="Italic">S</Emphasis><Superscript><Emphasis Type="Italic">p</Emphasis></Superscript> × <Emphasis Type="Italic">S</Emphasis><Superscript><Emphasis Type="Italic">q</Emphasis></Superscript>

We calculate \({\mathcal{S}^{{\it Diff}}(S^p \times S^q)}\), the smooth structure set of S ^p × S ^q , for p, q ≥ 2 and p + q ≥ 5. As a consequence we show that in general \({\mathcal{S}^{Diff}(S^{4j-1}\times S^{4k})}\) cannot admit a group structure such that the smooth surgery exact sequence is a long exact sequence of groups. We also show that the image of the forgetful map \({\mathcal{S}^{Diff}(S^{4j}\times S^{4k}) \rightarrow \mathcal{S}^{Top}(S^{4j}\times S^{4k})}\) is not in general a subgroup of the topological structure set.     

Codimension-<Emphasis Type="Italic">p</Emphasis> Paley–Wiener theorems

We obtain the generalized codimension-p Cauchy–Kovalevsky extension of the exponential function in R ^m =R ^p ⊕R ^q , where p>1, , and prove the corresponding codimension-p Paley–Wiener theorems.     

Difference sets with <Emphasis Type="Italic">n</Emphasis> = 5<Emphasis Type="Italic"> p</Emphasis><Superscript><Emphasis Type="Italic">r</Emphasis></Superscript>

Let D be a (v, k, λ)-difference set in an abelian group G, and (v, 31) = 1. If n = 5p ^r with p a prime not dividing v and r a positive integer, then p is a multiplier of D. In the case 31|v, we get restrictions on the parameters of such difference sets D for which p may not be a multiplier.