Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2001

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 5431 - 5460 of 6953

Full-Text Articles in Entire DC Network

Computation Of Overlap, Kinetic And Nuclear Attraction Integrals By A Novel Method, Gökhan Budak, Abdulhali̇k Karabulut, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n Jan 2001

Computation Of Overlap, Kinetic And Nuclear Attraction Integrals By A Novel Method, Gökhan Budak, Abdulhali̇k Karabulut, Lütfü Demi̇r, Nagi̇f Sefteroğlu Nabi̇yev, Yusuf Şahi̇n

Turkish Journal of Physics

A new way of computing overlap, kinetic and nuclear attraction integrals over Slater functions by means of optimized Gaussian expansion is proposed. This article is concerned with the construction of the general algorithm for evaluating the three integrals. These integral formulae presented in the form of a series whose terms are the analytical function of inter-atomic distances. In the present method, unlike many other popular methods, the numerical integration procedure is unnecessary since it does not contain the incomplete gamma function. The present scheme has been programmed in standard Fortran-77 and tested for various orbitals. The result of the calculation …

Go to article

Photospheric Line Profiles In Deneb (A2 Iae), Berahi̇tdi̇n Albayrak, Cemal Aydin, Dursun Koçer Jan 2001

Photospheric Line Profiles In Deneb (A2 Iae), Berahi̇tdi̇n Albayrak, Cemal Aydin, Dursun Koçer

Turkish Journal of Physics

In this study, the strong lines were examined to determine the effect of velocity gradient due to mass loss on the line profiles in the atmosphere of Deneb. The lines are formed in the optical depth range -1.14 < log \tau < -0.14. None were found to exibit any asymmetry.

Go to article

The Lattice Dynamics And The Elastic Behaviour Of Fcc And Bcc Ba, Yasemi̇n Özteki̇n Çi̇ftçi̇, Kemal Çolakoğlu Jan 2001

The Lattice Dynamics And The Elastic Behaviour Of Fcc And Bcc Ba, Yasemi̇n Özteki̇n Çi̇ftçi̇, Kemal Çolakoğlu

Turkish Journal of Physics

The two-body pairwise E.G.E.P. (Extended Generalized Exponantial Potential) type Morse potential and volume dependent energy are assumed to represent the total energy of the Ba crystal. The parametrized potential is used to calculate the second- and third-order elastic constants C_{ij} and C_{ijk}, pressure derivatives of bulk moduli and Grüneisen parameter \gamma . The phonon frequencies are also computed and plotted. The obtained results are compared with available experimental data and, in general, the agreement is good.

Go to article

Autoionization Resonances In The Simultaneous Excitation-Ionization Of Helium, Mevlut Dogan, Albert Crowe Jan 2001

Autoionization Resonances In The Simultaneous Excitation-Ionization Of Helium, Mevlut Dogan, Albert Crowe

Turkish Journal of Physics

The effect of autoionizing states on excitation-ionization processes has been investigated experimentally by observation of the electron impact ionization process leading to He^{ + }(2p) with the excitation energy region in helium corresponding to doubly excitated states above the second ionization threshold. Also, the process arising from the decay of the doubly excited `parity unfavoured' (2p^{2})^{3}P state of helium, is studied.

Go to article

On The Statistical Properties Of A Q-Oscillator, Abdullah Algin Jan 2001

On The Statistical Properties Of A Q-Oscillator, Abdullah Algin

Turkish Journal of Physics

Several statistical properties of the Coon-Baker-Yu (CBY) q-oscillator algebra are discussed. Particular emphasis is given to a careful derivation of second quantized particle statistics obtained via the CBY q-oscillator. It is outlined that, beside other limiting cases, the limit q = 0 of the CBY q-oscillator gives the Cuntz oscillator and the Fock space properties of both of these oscillators lead to various interesting results.

Go to article

Influence Of Above-Molecular Structure, Electronic And Ionic Phenomena On Durable Properties Of Polymer Dielectrics In The Electric Field, T. M. Veliyev, S. A. Abasov, M. J. Zeynalova, E. Hali̇lova, H. Memedov, I. Askerov, S. Aydoğu Jan 2001

Influence Of Above-Molecular Structure, Electronic And Ionic Phenomena On Durable Properties Of Polymer Dielectrics In The Electric Field, T. M. Veliyev, S. A. Abasov, M. J. Zeynalova, E. Hali̇lova, H. Memedov, I. Askerov, S. Aydoğu

Turkish Journal of Physics

Influence of above-molecular structure (AMS) on electrothermoluminescence, the altering time and the mechanic time of polymer dielectrics in strong electric fields that depend on temperature have been investigated. It has been shown that change of AMS considerably influenced the processes of injection and stabilization of charges as well as the solidity properties of polymers. It has been determined that the relaxation translations in large spherolite samples were observed at lower temperatures than the relaxation translations in small spherolite samples.

Go to article

Symplectic Maps To Projective Spaces And Symplectic Invariants, Denis Auroux Jan 2001

Symplectic Maps To Projective Spaces And Symplectic Invariants, Denis Auroux

Turkish Journal of Mathematics

After reviewing recent results on symplectic Lefschetz pencils and symplectic branched covers of \CP^2, we describe a new construction of maps from symplectic manifolds of any dimension to \CP^2 and the associated monodromy invariants. We also show that a dimensional induction process makes it possible to describe any compact symplectic manifold by a series of words in braid groups and a word in a symmetric group.

Go to article

The Topology Of Symplectic Manifolds, Robert E. Gompf Jan 2001

The Topology Of Symplectic Manifolds, Robert E. Gompf

Turkish Journal of Mathematics

A topological structure is introduced that seems likely to provide a complete topological characterization of compact symplectic manifolds. The article begins with a leisurely introduction to symplectic manifolds from a topological viewpoint. It then focuses on Thurston's construction of a symplectic structure on the total space of a fiber bundle. This is generalized to a technique for putting a symplectic structure on the domain of a J-holomorphic map. A topological structure called a hyperpencil on a compact 2n-manifold is then defined; this is motivated by the special case of a linear system of curves on an algebraic manifold, and it …

Go to article

Surface Bundles: Some Interesting Examples, Jim Bryan, Ron Donagi, Andras I. Stipsicz Jan 2001

Surface Bundles: Some Interesting Examples, Jim Bryan, Ron Donagi, Andras I. Stipsicz

Turkish Journal of Mathematics

We show two constructions of surface bundles over Riemann surfaces admitting nonvanishing signatures.

Go to article

Torus Fibrations On Symplectic Four-Manifolds, Ivan Smith Jan 2001

Torus Fibrations On Symplectic Four-Manifolds, Ivan Smith

Turkish Journal of Mathematics

This paper has two essentially unrelated halves. In the first we prove that a closed symplectic four-manifold admitting a fibration by connected, homologically essential Lagrangian tori with "tame" singularities, is fibre-preserving diffeomorphic to a K3 surface or to a torus bundle over a torus with first Betti number at least three. In the second, we prove that these torus bundles over tori admit Lefschetz pencils by genus three curves. It follows that the genus three mapping class group admits infinitely many inequivalent irreducible positive relations. Motivations for the questions are provided from mirror symmetry, integrable systems and Seiberg-Witten theory: in …

Go to article

Sections Of Lefschetz Fibrations And Stein Fillings, Andras I. Stipsicz Jan 2001

Sections Of Lefschetz Fibrations And Stein Fillings, Andras I. Stipsicz

Turkish Journal of Mathematics

Using Eliashberg's theorem about Stein fillings of S^3 we prove that a section of a Lefschetz fibration over S^2 has nonnegative square. This observation, in particular, implies that the identity element 1\in \Gamma _g ^1 in the mapping class group of a genus-g surface with one boundary component cannot be written as a product of positive Dehn twists.

Go to article

Floer Homology And Its Continuity For Non-Compact Lagrangian Submanifolds, Yong-Geum Oh Jan 2001

Floer Homology And Its Continuity For Non-Compact Lagrangian Submanifolds, Yong-Geum Oh

Turkish Journal of Mathematics

We give a construction of the Floer homology of the pair of vnon-compact Lagrangian submanifolds, which satisfies natural continuity property under the Hamiltonian isotopy that moves the infinity but leaves the intersection set of the pair compact. This construction uses the concept of Lagrangian cobordism and certain singular Lagrangian submanifolds. We apply this construction to conormal bundles (or varieties) in the cotangent bundle, and relate it to a conjecture made by MacPherson on the intersection theory of the characteristic Lagrangian cycles associated to the perverse sheaves constructible to a complex stratification on the complex algebraic manifold.

Go to article

The Canonical Class Of A Symplectic Four Manifold, Ronald Fintushel, Ronald Stern Jan 2001

The Canonical Class Of A Symplectic Four Manifold, Ronald Fintushel, Ronald Stern

Turkish Journal of Mathematics

In this article we present examples of simply connected symplectic 4-manifolds X whose canonical classes are represented by complicated disjoint unions of symplectic submanifolds of X: Theorem. Given finite collections {g_i}, {m_i}, i=1,...,n, of positive integers, there is a minimal symplectic simply connected 4-manifold X whose canonical class is represented by a disjoint union of embedded symplectic surfaces K ~ S_{g_1,1} « ... « S_{g_1,m_1} « ... « S_{g_n,1} «... « S{g_n,m_n} where S_{g_i,j} is a surface of genus g_i. Furthermore, c_1^2(X) = c_h(X) - (2+ b) where b= S{i=1}^n m_i is the total number of connected components of the …

Go to article

A Partial Order On The Group Of Contactomorphisms Of $\R^{2n+1}$ Via Generating Functions, Mohan Bhupal Jan 2001

A Partial Order On The Group Of Contactomorphisms Of $\R^{2n+1}$ Via Generating Functions, Mohan Bhupal

Turkish Journal of Mathematics

In this note we construct a nontrivial partial order on the identity component of the group of compactly supported contactomorphisms of \R^{2n+1} using the method of generating functions. Our construction is in the framework of the theory developed by Viterbo in the paper \cite{V} wherein, among other things, he showed how one could use generating functions to construct a partial order on the group of compactly supported Hamiltonian symplectomorphisms of \R^{2n}.

Go to article

Knotting Of Algebraic Curves In Complex Surfaces, Sergey Finashin Jan 2001

Knotting Of Algebraic Curves In Complex Surfaces, Sergey Finashin

Turkish Journal of Mathematics

For any d\ge 5, I constructed infinitely many pairwise smoothly non-equivalent surfaces F\subset\Cp{2} homeomorphic to a non-singular algebraic curve of degree d, realizing the same homology class as such a curve and having abelian fundamental group \pi_1(\Cp2\stmin F). It is a special case of a more general theorem, which concerns for instance those algebraic curves, A, in a simply connected algebraic surface, X, which admit irreducible degenerations to a curve A_0, with a unique singularity of the type X_9, and such that A\cite A>16.

Go to article

The Verlinde Algebra Is Twisted Equivariant K-Theory, Daniel S. Freed Jan 2001

The Verlinde Algebra Is Twisted Equivariant K-Theory, Daniel S. Freed

Turkish Journal of Mathematics

The Verlinde algebra, which mathematically appears in the theory of loop groups and is related to moduli spaces of bundles over curves, turns out to be describable in terms of K-theory. This is a joint discovery with M. Hopkins and C. Teleman. Here we explain in heuristic terms how this fits naturally into ideas about the Chern-Simons topological field theory.

Go to article

Topological Quantum Field Theory And Hyperkähler Geometry, Justin Sawon Jan 2001

Topological Quantum Field Theory And Hyperkähler Geometry, Justin Sawon

Turkish Journal of Mathematics

Rozansky and Witten proposed a 3-dimensional sigma-model whose target space is a hyperkähler manifold. They conjectured that this theory has an associated TQFT, with vector spaces given by certain cohomology groups of the hyperkähler manifold. On the other hand, there is a certain modified TQFT constructed by Murakami and Ohtsuki using the universal quantum invariant. We explain how the Rozansky-Witten TQFT can be obtained from the latter by applying a "hyperkähler weight system".

Go to article

G-Bundles On Abelian Surfaces, Hyperk\"Aler Manifolds, And Stringy Hodge Numbers, Jim Bryan, Ron Donagi, Naichung Conan Leung Jan 2001

G-Bundles On Abelian Surfaces, Hyperk\"Aler Manifolds, And Stringy Hodge Numbers, Jim Bryan, Ron Donagi, Naichung Conan Leung

Turkish Journal of Mathematics

We study the moduli space M_{G} (A) of flat G-bundles on an Abelian surface A, where G is a compact, simple, simply connected, connected Lie group. Equivalently, M_{G} (A) is the (coarse) moduli space of s-equivalence classes of holomorphic semi-stable G^{\cnums }-bundles with trivial Chern classes. M_{G} (A) has the structure of a hyperk\"ahler orbifold. We show that when G is Sp(n) or SU (n), M_{G} (A) has a natural hyperk\"ahler desingularization which we exhibit as a moduli space of G^{\cnums }-bundles with an altered stability condition. In this way, we obtain the two known families of hyperk\"ahler manifolds, the …

Go to article

On The Tautological Ring Of \Bar{\Mathcal{M}}_{G,N}, Tom Graber, Ravi Vakil Jan 2001

On The Tautological Ring Of \Bar{\Mathcal{M}}_{G,N}, Tom Graber, Ravi Vakil

Turkish Journal of Mathematics

We prove that the dimension 0 part of the tautological ring of the moduli space of stable pointed curves is one-dimensional. This provides the first genus-free evidence for a conjecture of Faber and Pandharipande that the tautological ring of the moduli space is Gorenstein, answering in the affirmative a question of Hain and Looijenga.

Go to article

Cover And Contents Jan 2001

Cover And Contents

Turkish Journal of Mathematics

No abstract provided.

Go to article

Induced Cat^1-Groups, Murat Alp Jan 2001

Induced Cat^1-Groups, Murat Alp

Turkish Journal of Mathematics

In this paper we define the pullback cat^1-group and show that this Pullback has a right adjoint which is the induced cat^1-group. Later we show that this right adjoint is a pushout of category of cat^1-groups. We calculate the Peiffer subgroups to find a finite group of the source of induced cat^1-groups. The generating set of Peiffer subgroups are also given in this paper. All results are corrected by a GAP[13] program package in [4]. This paper also contains the some computational examples which are the calculation-induced cat^1-group and comparative times between the induced crossed modules and induced cat^1-groups.

Go to article

A Class Of Monoids Embeddable In A Group, Ebru Keyman Jan 2001

A Class Of Monoids Embeddable In A Group, Ebru Keyman

Turkish Journal of Mathematics

In this paper, we develop a new method to show that a monoid, given by a certain kind of presentation, embeds in a group. A mathematical device called the diamond condition was used in [5] to prove that the singular braid monoid SB_n embeds. Motivated by this, we consider monoid presentations which have the basic properties of the presentation of the singular braid monoid. In the same way as in [5], we prove that the monoid embeds. The proof of the diamond condition is completely geometric in [5], but here we prove it by using elementary algebraic properties.

Go to article

On The Semi-Markovian Random Walk Process With Reflecting And Delaying Barrriers, Selahatti̇n Maden Jan 2001

On The Semi-Markovian Random Walk Process With Reflecting And Delaying Barrriers, Selahatti̇n Maden

Turkish Journal of Mathematics

In this paper, a semi-Markovian random walk process X(t) with reflecting barrier on the zero-level and delaying barrier on the \beta(\beta>0 )-level and the first falling moment of the process into the delaying barrier, (\gamma), are considered. Some probability characteristics of \gamma , such as its distribution function, moment generating function and expected value are calculated.

Go to article

Formula For The Highly Regularized Trace Of The Sturm-Liouville Operator With Unbounded Operator Coefficients Having Singularity, İnci̇ Albayrak, Oya Baykal, Erdal Gül Jan 2001

Formula For The Highly Regularized Trace Of The Sturm-Liouville Operator With Unbounded Operator Coefficients Having Singularity, İnci̇ Albayrak, Oya Baykal, Erdal Gül

Turkish Journal of Mathematics

In this work, a formula for the n^{th} regularized trace of the Sturm-Liouville operator with unbounded operator coefficients having singularity is obtained

Go to article

Inequalities For The Vibrating Clamped Plate Problem, Kimberley Mchale, Ünal Ufuktepe Jan 2001

Inequalities For The Vibrating Clamped Plate Problem, Kimberley Mchale, Ünal Ufuktepe

Turkish Journal of Mathematics

We study the eigenvalues of the vibrating clamped plate problem. We have made improvements on the bounds of the ratios of the eigenvalues of the biharmonic operator (clamped plate) using the methods of Payne, Polya, and Weinberger. The difference in our proof lies mainly with the trial functions and the orthogonality arguments. While Payne, Polya, and Weinberger and Hile and Yeh project away components along u_1,u_2,...,u_k to meet the orthogonality conditions,we use a translation/rotation argument to meet these conditions.

Go to article

On The Expansions In Eigenfunctions Of Hill's Operator, Fi̇li̇z Aras, Gusei̇n Sh Gusei̇nov Jan 2001

On The Expansions In Eigenfunctions Of Hill's Operator, Fi̇li̇z Aras, Gusei̇n Sh Gusei̇nov

Turkish Journal of Mathematics

In this paper we show how one can deduce the Titchmarsh expansion formula in eigenfunctions of Hill's operator from the Gel'fand expansion formula.

Go to article

Global Convergence For Discrete Dynamical Systems And Forward Neural Networks, Asuman G. Aksoy, Mario Martelli Jan 2001

Global Convergence For Discrete Dynamical Systems And Forward Neural Networks, Asuman G. Aksoy, Mario Martelli

Turkish Journal of Mathematics

Using a theoretical result regarding the global stability of discrete dynamical systems of lower triangular form, we establish convergence properties of forward neural networks when the neuron response functions fail to be continuous.

Go to article

Cover And Contents Jan 2001

Cover And Contents

Turkish Journal of Mathematics

No abstract provided.

Go to article

On Modified Baskakov Operators On Weighted Spaces, Nurhayat İspi̇r Jan 2001

On Modified Baskakov Operators On Weighted Spaces, Nurhayat İspi̇r

Turkish Journal of Mathematics

The author presents a modification of the Baskakov operator for the intervals [0,b_{n}], where b_{n} is an increasing sequence of positive numbers with either finite or infinite limit. Convergence properties of such an operator for continuous and differentiable functions in weighted space are established.

Go to article

On The Centroid Of The Prime Gamma Rings Ii, Mehmet Ali̇ Öztürk, Young Bae Jun Jan 2001

On The Centroid Of The Prime Gamma Rings Ii, Mehmet Ali̇ Öztürk, Young Bae Jun

Turkish Journal of Mathematics

The aim of this paper is to study the properities of the extended centroid of the prime \Gamma-rings. Main results are the following theorems: (1) Let M be a simple \Gamma-ring with unity. Suppose that for some a\neq 0 in M we have a\gamma_{1} x\gamma_{2} a\beta_{1} y\beta_{2}a = a\beta_{1} y\beta_{2} a\gamma_{1} x\gamma_{2}a for all x, y\in M and \gamma_{1} ,\gamma_{2} ,\beta_{1} ,\beta_{2} \in \Gamma. Then M is isomorphic onto the \Gamma-ring D_{n,m}, where D_{n,m} is the additive abelian group of all rectangular matrices of type n\times m over a division ring D and \Gamma is a nonzero subgroup of the …

Go to article

First Prev Next Last