Bases of admissible rules for <Emphasis Type="Italic">K</Emphasis>-saturated logics

Admissible inference rules for table modal and superintuitionistic logics are investigated. K-saturated logics are defined semantically. Such logics are proved to have finite bases for admissible inference rules in finitely many variables. __________ Translated from Algebra i Logika, Vol. 47, No. 6, pp. 750–761, November–December, 2008.     

Towards the Hurwitz Generation of G<Subscript>sc</Subscript>(E<Subscript>6</Subscript>, <Emphasis Type="Italic">q</Emphasis>)

The paper is devoted to the problem concerning the Hurwitz generation of the group G_sc(E₆, q). All possibilities for Hurwitz generators, except for just one, are excluded. Bibliography: 25 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 305, 2003, pp. 228–237.     

Estimates of Distances Between Sums of the Spaces ℓ<Stack><Subscript>n</Subscript><Superscript>p</Superscript></Stack>. II

We study classical, modified, and weak Banach-Mazur distances between sums of the spaces ℓ _n ^p . We calculate explicitly the classical and weak Banach-Mazur distances between sums of the spaces ℓ _n ^p and obtain bounds for ratios of distances between sums of the spaces ℓ _n ^p . Bibliography: 14 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 303, 2003, pp. 203–217.     

Root Decomposition of the Ternary Malcev Algebra <Emphasis Type="Italic">M</Emphasis><Subscript>8</Subscript>

A root decomposition is constructed of the simple eight-dimensional ternary Malcev algebra M ₈. In result, M ₈ is equipped with a structure of a Z ₃-graded ternary algebra.Original Russian Text Copyright © 2005 Pozhidaev A. P.The author was supported by the Russian Science Support Foundation and partially by the Russian Foundation for Basic Research (Grant 05-01-00230).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 4, pp. 901–906, July–August, 2005.     

Best Polynomial Approximations in <Emphasis Type="Italic">L</Emphasis><Subscript>2</Subscript> and Widths of Some Classes of Functions

We obtain the exact values of extremal characteristics of a special form that connect the best polynomial approximations of functions f(x) ∈ L ₂ ^r (r ∈ ℤ₊) and expressions containing moduli of continuity of the kth order ω_k(f(^r), t). Using these exact values, we generalize the Taikov result for inequalities that connect the best polynomial approximations and moduli of continuity of functions from L ₂. For the classes (k, r, Ψ_*) defined by ω _k(f ^(r), t) and the majorant , we determine the exact values of different widths in the space L₂.__________Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 56, No. 11, pp. 1458–1466, November, 2004.     

Best Approximations of <Emphasis Type="Italic">q</Emphasis>-Ellipsoids in Spaces <Emphasis Type="Italic">S</Emphasis><Stack><Subscript>ϕ</Subscript><Superscript><Emphasis Type="Italic">p</Emphasis>,μ</Superscript></Stack>

We find exact values of the best approximations and basic widths of q-ellipsoids in the spaces S _ϕ ^p,μ for q > p > 0.__________Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 56, No. 10, pp. 1378 – 1383, October, 2004.     

Best Approximations and Kolmogorov and Trigonometric Widths of the Classes <Emphasis Type="Italic">B</Emphasis><Stack><Subscript><Emphasis Type="Italic">p</Emphasis>,θ</Subscript><Superscript>Ω</Superscript></Stack> of Periodic Functions of Many Variables

We obtain estimates exact in order for the best approximations and Kolmogorov and trigonometric widths of the classes B _p,θ ^Ω of periodic functions of many variables in the space L ^q for certain values of the parameters p and q.__________Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 56, No. 11, pp. 1557–1568, November, 2004.     

Interpolation of operators of weak type (ϕ<Subscript>0</Subscript>, ψ<Subscript>0</Subscript>, ϕ<Subscript>1</Subscript>, ψ<Subscript>1</Subscript>) in Lorentz spaces

We prove theorems on interpolation of quasilinear operators of weak type (ϕ₀, ψ₀, ϕ₀, ψ₁) in Lorentz spaces. The operators under study are analogs of the Calderón operator and the Benett operator for concave and convex functions ϕ₀(t), ψ₀(t), ϕ₁(t), and ψ₁(t). __________ Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 57, No. 11, pp. 1490–1507, November, 2005.     

PSPACE complexity of modal logic <Emphasis Type="Italic">K D</Emphasis>45<Subscript>n</Subscript>

We study sequent calculus for multi-modal logic K D45_n and its complexity. We introduce a loop-check free sequent calculus. Loop-check is eliminated by using the marked modal operator □_i^•, which is used as an alternative to sequents with histories ([8], [3], [5]). All inference rules are invertible or semi-invertible. To get this, we use or branches beside common and branches. We prove the equivalence between known sequent calculus and our newly introduced efficient sequent calculus. We concentrate on the complexity analysis of the introduced sequent calculus for multi-modal logic K D45_n. We prove that the space complexity of the given calculus is polynomial (O(l ³)). We show the maximum height of the constructed derivation tree that leads to the reduction of the time and space complexity. We present a decision algorithm for multi-modal logic K D45_n and some nontrivial examples to improve the introduced loop-check free sequent calculus.     

The Number of Spanning Trees in <Emphasis Type="Italic">K</Emphasis><Subscript><Emphasis Type="Italic">n</Emphasis></Subscript>-Complements of Quasi-Threshold Graphs

In this paper we examine the classes of graphs whose K_n-complements are trees or quasi-threshold graphs and derive formulas for their number of spanning trees; for a subgraph H of K_n, the K_n-complement of H is the graph K_n–H which is obtained from K_n by removing the edges of H. Our proofs are based on the complement spanning-tree matrix theorem, which expresses the number of spanning trees of a graph as a function of the determinant of a matrix that can be easily constructed from the adjacency relation of the graph. Our results generalize previous results and extend the family of graphs of the form K_n–H admitting formulas for the number of their spanning trees.Final version received: March 18, 2004     

Coxeter group actions on <Subscript>4</Subscript><Emphasis Type="Italic">F</Emphasis><Subscript>3</Subscript>(1) hypergeometric series

In this paper we investigate a certain linear combination K([(x)\vec])=K(a;b,c,d;e,f,g)K(\vec{x})=K(a;b,c,d;e,f,g) of two Saalschutzian hypergeometric series of type ₄ F ₃(1). We first show that K([(x)\vec])K(\vec{x}) is invariant under the action of a certain matrix group G _K , isomorphic to the symmetric group S ₆, acting on the affine hyperplane V={(a,b,c,d,e,f,g)∈ℂ⁷:e+f+g−a−b−c−d=1}. We further develop an algebra of three-term relations for K(a;b,c,d;e,f,g). We show that, for any three elements μ ₁,μ ₂,μ ₃ of a certain matrix group M _K , isomorphic to the Coxeter group W(D ₆) (of order 23040) and containing the above group G _K , there is a relation among K(m₁[(x)\vec])K(\mu_{1}\vec{x}), K(m₂[(x)\vec])K(\mu_{2}\vec{x}), and K(m₃[(x)\vec])K(\mu_{3}\vec{x}), provided that no two of the μ _j ’s are in the same right coset of G _K in M _K . The coefficients in these three-term relations are seen to be rational combinations of gamma and sine functions in a,b,c,d,e,f,g.     

<Emphasis Type="Italic">S</Emphasis><Subscript><Emphasis Type="Italic">k</Emphasis>,exp</Subscript> Does Not Prove NP = <Emphasis Type="Italic">co</Emphasis>-NP Uniformly

The notion of a uniform sequent-calculus proof is introduced. It is shown that a strengthening, S_k,exp , of the well-studied bounded arithmetic system S_k of Buss does not prove NP = co-NP with a uniform proof. A slightly stronger result that S_k,exp cannot prove uniformly for 2 ≤ k′ ≤ k is also established. A modification of the technique used is applied to show that S_k,exp is unable to prove the Davis-Putnam-Robinson-Matiyasevich theorem. Generalizations of these results to higher levels of the Grzegorczyck hierarchy are presented. Bibliography: 21 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 304, 2003, pp. 99–120.     

On Generalized Hardy Sums <Emphasis Type="Italic">s</Emphasis><Subscript>5</Subscript>(<Emphasis Type="Italic">h,k</Emphasis>)

The aim of this paper is to study generalized Hardy sums s ₅(h, k). By using mediants and the adjacent difference of Farey fractions, we establish a relationship between s ₅(h, k) and Farey fractions. Using generalized Dedekind sums and a generalized periodic Bernoulli function, we define generalized Hardy sums s _5,p (h,k). A relationship between s _5,p (h, k) and the Hurwitz zeta function is established. By using the definitions of Lambert series and cotπz, we establish a relationship between s ₅(h,k) and Lambert series.__________Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 56, No. 10, pp. 1434–1440, October, 2004.     

Gröbner-Shirshov bases for the lie algebra <Emphasis Type="Italic">A</Emphasis><Subscript><Emphasis Type="Italic">n</Emphasis></Subscript>

We estimate Gröbner-Shirshov bases for the Lie algebra A_n given arbitrary orders of generators (nodes of a Dynkin graph). Previously, the Gröbner-Shirshov basis was computed in [1] for the particular case where nodes of the Dynkin graph are ordered successively.Supported by RFBR grant Nos. 05-01-00230 and 02-01-00258 and by the Council for Grants (under RF President) and State Aid of Fundamental Science Schools, project NSh-2069.2003.1.__________Translated from Algebra i Logika, Vol. 44, No. 2, pp. 131–147, March–April, 2005.     

The -conjecture and equivariant <Emphasis Type="Italic">e</Emphasis><Subscript><Emphasis Type="Italic">C</Emphasis></Subscript>-invariants

Let X be a smooth closed oriented non-spin 4-manifold with even intersection form kE₈nH (n1). The -conjecture states that n is greater than or equal to |k|. In this paper we give a proof of the -conjecture. The strategy of this paper is to use the finite dimensional approximation of the map induced from the Seiberg-Witten equations and equivariant e_C-invariants as in the paper of M. Furuta and Y. Kametani.Mathematics Subject Classification (1991): 57R55This work was supported by Korea Research Foundation Grant (KRF–2002–003–C00011).     

<Emphasis Type="Italic">L</Emphasis><Subscript><Emphasis Type="Italic">p</Emphasis></Subscript>-Boundedness of general index transforms

We establish the boundedness properties in L _p for a class of integral transformations with respect to an index of hypergeometric functions. In particular, by using the Riesz-Thorin interpolation theorem, we get the corresponding results in L _p (R ₊), 1 p 2, for the Kontorovich-Lebedev, Mehler-Fock, and Olevskii index transforms. An inversion theorem is proved for a general index transformation. The case p=2 is known as the Plancherel-type theory for this class of transformations.__________Published in Lietuvos Matematikos Rinkinys, Vol. 45, No. 1, pp. 127–147, January–March, 2005.     

On <Emphasis Type="Italic">K</Emphasis><Subscript><Emphasis Type="Italic">1</Emphasis></Subscript> of a self-product of a curve

We present elements of H¹(C×C, ᵊ6₂) for certain specific curves C. The image of the element under the boundary map arising from the localization sequence of K-theory is the graph of frobenius endomorphism of the reduction of the curve modulo 3.     

On the inverse of the generator of a bounded <Emphasis Type="Italic">C</Emphasis><Subscript>0</Subscript>-semigroup

Let A be the generator of a uniformly bounded C ₀-semigroup in a Banach space B, and let A have a densely defined inverse A ^-1 . We present sufficient conditions on the resolvent (A-I ^-1, Re > 0, under which A ^-1 is also the generator of a uniformly bounded C ₀-semigroup.Dedicated to V. B. Lidskii on the occasion of his eightieth birthdayTranslated from Funktsionalnyi Analiz i Ego Prilozheniya, Vol. 38, No. 4, pp. 6–12, 2004Original Russian Text Copyright © by A. M. Gomilko     

Exact <Emphasis Type="Italic">L</Emphasis><Subscript><Emphasis Type="Italic">2</Emphasis></Subscript>-small ball behavior of integrated Gaussian processes and spectral asymptotics of boundary value problems

We find the exact small deviation asymptotics for the L₂-norm of various m-times integrated Gaussian processes closely connected with the Wiener process and the Ornstein – Uhlenbeck process. Using a general approach from the spectral theory of linear differential operators we obtain the two-term spectral asymptotics of eigenvalues in corresponding boundary value problems. This enables us to improve the recent results from [15] on the small ball asymptotics for a class of m-times integrated Wiener processes. Moreover, the exact small ball asymptotics for the m-times integrated Brownian bridge, the m-times integrated Ornstein – Uhlenbeck process and similar processes appear as relatively simple examples illustrating the developed general theory.Partially supported by grants of RFBR 01-01-00245 and 02-01-01099.