DSpace Collection: Volume 37, Number 4
http://hdl.handle.net/10525/2717
Serdica Mathematical Journal Volume 37, Number 4, 2011The Collection's search engineSearch the Channelsearch
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(2,3)-generation of the groups PSL6(q)
http://hdl.handle.net/10525/2744
Title: (2,3)-generation of the groups PSL6(q)<br/><br/>Authors: Tabakov, K.; Tchakerian, K.<br/><br/>Abstract: We prove that the group PSL6(q) is (2,3)-generated for any q. In fact, we provide explicit generators x and y of orders 2 and 3, respectively, for the group SL6(q).<br/><br/>Description: 2010 Mathematics Subject Classification: 20F05, 20D06.Sat, 01 Jan 2011 00:00:00 GMTOn strongly regular graphs with m2 = qm3 and m3 = qm2
http://hdl.handle.net/10525/2743
Title: On strongly regular graphs with m2 = qm3 and m3 = qm2<br/><br/>Authors: Lepovic, Mirko<br/><br/>Abstract: We say that a regular graph G of order n and degree r і 1 (which is not the complete graph) is strongly regular if there exist non-negative integers t and q such that |SiЗSj| = t for any two adjacent vertices i and j, and |SiЗSj| = q for any two distinct non-adjacent vertices i and j, where Sk denotes the neighborhood of the vertex k. Let l1 = r, l2 and l3 be the distinct eigenvalues of a connected strongly regular graph. Let m1 = 1, m2 and m3 denote the multiplicity of r, l2 and l3, respectively. We here describe the parameters n, r, t and q for strongly regular graphs with m2 = qm3 and m3 = qm2 for q = 2, 3, 4.<br/><br/>Description: 2010 Mathematics Subject Classification: 05C50.Sat, 01 Jan 2011 00:00:00 GMTWeighted composition followed by differentiation between weighted Banach spaces of holomorphic functions
http://hdl.handle.net/10525/2742
Title: Weighted composition followed by differentiation between weighted Banach spaces of holomorphic functions<br/><br/>Authors: Wolf, Elke<br/><br/>Abstract: Let f be an analytic self-map of the open unit disk D in the complex plane and y be an analytic map on D. Such maps induce a weighted composition operator followed by differentiation DCf, y acting between weighted Banach spaces of holomorphic functions. We characterize boundedness and compactness of such operators in terms of the involved weights as well as the functions f and y.<br/><br/>Description: 2010 Mathematics Subject Classification: 47B33, 47B38.Sat, 01 Jan 2011 00:00:00 GMTGrowth of some varieties of Leibniz-Poisson algebras
http://hdl.handle.net/10525/2741
Title: Growth of some varieties of Leibniz-Poisson algebras<br/><br/>Authors: Ratseev, S. M.<br/><br/>Abstract: Let V be a variety of Leibniz-Poisson algebras over an arbitrary field whose ideal of identities contains the identities {{x1,y1},{x2,y2},ј,{xm,ym}} = 0, {x1,y1}·{x2,y2}· ј ·{xm,ym} = 0 for some m. It is shown that the exponent of V exists and is an integer.<br/><br/>Description: 2010 Mathematics Subject Classification: 17A32, 17B63.Sat, 01 Jan 2011 00:00:00 GMTEquiconvergence and equisummability of Jacobi series
http://hdl.handle.net/10525/2740
Title: Equiconvergence and equisummability of Jacobi series<br/><br/>Authors: Boychev, Georgi<br/><br/>Abstract: In this paper we give some results concerning the equiconvergence and equisummability of series in Jacobi polynomials.<br/><br/>Description: 2010 Mathematics Subject Classification: 33C45, 40G05.Sat, 01 Jan 2011 00:00:00 GMTPolynomial automorphisms over finite fields: Mimicking tame maps by the Derksen group
http://hdl.handle.net/10525/2739
Title: Polynomial automorphisms over finite fields: Mimicking tame maps by the Derksen group<br/><br/>Authors: Maubach, Stefan; Willems, Roel<br/><br/>Abstract: If F is a polynomial automorphism over a finite field Fq in dimension n, then it induces a permutation pqr(F) of (Fqr)n for every r О N*. We say that F can be "mimicked" by elements of a certain group of automorphisms G if there are gr О G such that pqr(gr) = pqr(F).Derksen's theorem in characteristic zero states that the tame automorphisms in dimension n і 3 are generated by the affine maps and the one map (x1+x22, x2,ј, xn). We show that Derksen's theorem is not true in characteristic p in general. However, we prove a modified, weaker version of Derksen's theorem over finite fields: we introduce the Derksen group DAn(Fq), n і 3, which is generated by the affine maps and one well-chosen nonlinear map, and show that DAn(Fq) mimicks any element of TAn(Fq). Also, we do give an infinite set E of non-affine maps which, together with the affine maps, generate the tame automorphisms in dimension 3 and up. We conjecture that such a set E cannot be finite.We consider the subgroups GLINn(k) and GTAMn(k). We prove that for k a finite field, these groups are equal if and only if k\not = F2. The latter result provides a tool to show that a map is not linearizable.<br/><br/>Description: 2010 Mathematics Subject Classification: 14L99, 14R10, 20B27.Sat, 01 Jan 2011 00:00:00 GMTDouble complexes and vanishing of Novikov cohomology
http://hdl.handle.net/10525/2738
Title: Double complexes and vanishing of Novikov cohomology<br/><br/>Authors: Hüttemann, Thomas<br/><br/>Abstract: We consider non-standard totalisation functors for double complexes, involving left or right truncated products. We show how properties of these imply that the algebraic mapping torus of a self map h of a cochain complex of finitely presented modules has trivial negative Novikov cohomology, and has trivial positive Novikov cohomology provided h is a quasi-isomorphism. As an application we obtain a new and transparent proof that a finitely dominated cochain complex over a Laurent polynomial ring has trivial (positive and negative) Novikov cohomology.<br/><br/>Description: 2010 Mathematics Subject Classification: Primary 18G35; Secondary 55U15.Sat, 01 Jan 2011 00:00:00 GMTOn the generalized Kato spectrum
http://hdl.handle.net/10525/2737
Title: On the generalized Kato spectrum<br/><br/>Authors: Benharrat, Mohammed; Messirdi, Bekkai<br/><br/>Abstract: We show that the symmetric difference between the generalized Kato spectrum and the essential spectrum defined in [7] by sec(T) = {l О C ; R(lI-T) is not closed } is at most countable and we also give some relationship between this spectrum and the SVEP theory.<br/><br/>Description: 2010 Mathematics Subject Classification: 47A10.Sat, 01 Jan 2011 00:00:00 GMTDirac type condition and Hamiltonian graphs
http://hdl.handle.net/10525/2736
Title: Dirac type condition and Hamiltonian graphs<br/><br/>Authors: Zhao, Kewen<br/><br/>Abstract: In 1952, Dirac introduced the degree type condition and proved that if G is a connected graph of order n і 3 such that its minimum degree satisfies d(G) і n/2, then G is Hamiltonian. In this paper we investigate a further condition and prove that if G is a connected graph of order n і 3 such that d(G) і (n-2)/2, then G is Hamiltonian or G belongs to four classes of well-structured exceptional graphs.<br/><br/>Description: 2010 Mathematics Subject Classification: 05C38, 05C45.Sat, 01 Jan 2011 00:00:00 GMT