conditions of regularity in cone metric spaces in this paper we prove some fixed points results on cone metric spaces for maps satisfying general contractive type conditions among other things we extend some results of nguyen 11 from metric spaces to cone metric spaces the example is included

partially ordered cone metric spaces and coupled fixed point results bhaskar and lakshmikantham t g bhaskar v lakshmikantham fixed point theorems in partially ordered metric spaces and applications nonlinear anal 65 2006 1379 1393 studied the coupled coincidence point of a mapping f from xxx into x and a mapping g from x into x e karapinar e karapinar couple fixed point theorems for nonlinear contractions in cone metric spaces comput math appl 2010 doi 10 1016 j camwa 2010 03 062 proved some results of the coupled coincidence point of a mapping f from xxx into x and a mapping g from x into x over normal cones without regularity in the present paper we prove that coupled coincidence fixed point theorems over cone metric spaces are not necessarily normal our results generalize several well known comparable results in the literature

iterative approximation to a coincidence point of two mappings in this article two methods for approximating the coincidence point of two mappings are studied and moreover rates of convergence for both methods are given these results are illustrated by several examples in particular we apply such results to study the convergence and their rate of convergence of these methods to the solution of a nonlinear integral equation and of a nonlinear differential equation

fixed points of weak contractions in cone metric spaces abstract cone metric spaces are generalizations of metric spaces where the metric is banach space valued weak contractions are generalizations of the banach s contraction mapping which have been studied by several authors in the present work we establish a unique fixed point result for weak contractions in cone metric spaces our result is supported by an example

coherency of su 1 1 barut girardello type and entanglement for spherical harmonics barut girardello coherent states corresponding to the l m and l m integer discrete irreducible representations of su 1 1 lie algebra are calculated by the spherical harmonics ylm their explicit compact forms and also to realize the resolution of the identity their corresponding positive definite measures on the complex plane are obtained in terms of the known functions it is also shown that coherent states of both positive and negative representations separately lead us to construct new representation bases for su 1 1 lie algebra then it is shown that the su 1 1 barut girardello coherent states corresponding to two particles containing the spatial parity symmetries of a bipartite quantum system can be entangled in ten different ways

kkm mappings in cone metric spaces and some fixed point theorems abstract in this paper we define kkm mappings in cone metric spaces and define n cone metric spaces to obtain some fixed point theorems and hence generalize the results obtained in a amini m fakhar j zafarani kkm mapping in metric spaces nonlinear anal 60 2005 1045 1052

coincidence and common fixed and periodic point theorems in cone metric spaces the aim of this paper is to show the existence of coincidence and fixed points for mappings satisfying property e a in cone metric spaces also we give periodic point theorems in cone metric spaces

multivalued f weakly picard mappings recently m berinde and v berinde m berinde v berinde on a general class of multi valued weakly picard mappings j math anal appl in press extended the notion of weak contraction from single valued mappings to multivalued mappings and obtained some convergence theorems for the picard iteration associated with multivalued weak contractions we further extended the notion of weak contraction and introduced the notions of multivalued f weak contraction and generalized multivalued f weak contraction we obtain some coincidence and fixed point theorems our results extend m berinde v berinde on a general class of multi valued weakly picard mappings j math anal appl in press and those contained therein

boyd wong type common fixed point results in cone metric spaces abstract some common fixed point results in cone metric spaces of c di bari and p vetro c di bari p vetro pairs and common fixed points in cone metric spaces rend cir mat palermo 57 2008 279 285 as well as p raja and s m vaezpour p raja s m vaezpour some extensions of banach s contraction principle in complete metric spaces fixed point theory appl 2008 doi 10 1155 2008 768294 are extended using generalized contractive type conditions and cones which may be nonnormal cone metric versions of several well known results such as boyd wong s theorem d w boyd j s wong on nonlinear contractions proc amer math soc 20 1969 458 464 are obtained as special cases

a common fixed point theorem for compatible quasi contractive self mappings in metric spaces a common fixed point theorem for weakly commuting quasi contractive self mappings with contracting orbital diameters in metric spaces v berinde a common fixed point theorem for quasi contractive type mappings ann univ sci budapest 46 2003 81 90 is extended to the more general class of compatible quasi contractive self mappings our result does extend and generalize numerous related results in literature

semiclassical resolvent estimates for n body schrodinger operators in this paper we prove for a generalized n body schrodinger operator that the non trapping condition on the classical hamiltonian and all classical subhamiltonians is both necessary and sufficient for obtaining good semiclassical bounds on the boundary values of the resolvent and their energy derivatives we accomplish this by generalizing gerard s geometrical construction of an escape function for three body problems to n body problems this work is motivated by a recent paper of ch gerard 3 in which he proved for three body problems that if the classical hamiltonian and all classical sub hamiltonians are non trapping at the energy e then the resolvent of the corresponding semiclassical schrodinger operator satisfies the estimates

some common fixed point theorems for a family of mappings in metrically convex spaces abstract in the present paper some common fixed point theorems for a sequence and a pair of nonself mappings in complete metrically convex metric spaces are proved which generalize such results due to khan et al m s khan h k pathak m d khan some fixed point theorems in metrically convex spaces georgian math j 7 3 2000 523 530 assad n a assad on a fixed point theorem of kannan in banach spaces tamkang j math 7 1976 91 94 chatterjea s k chatterjea fixed point theorems c r acad bulgare sci 25 1972 727 730 and several others some related results are also discussed

common fixed point theorems for a mixed family of fuzzy and crisp mappings we prove a common fixed point theorem for the nonfuzzy mappings and a sequence of fuzzy mappings in a linear metric space under hybrid d compatible condition our result is more general than those of lee et al fuzzy sets and systems 2000a submitted and many others biologically relevant involvements are raised with respect to brain functioning

coincidence and fixed point theorems for generalized ψ φ weak nonlinear contraction in ordered k metric spaces in this paper we establish coincidence and fixed point theorems for a pair of mappings satisfying a new generalized j f weak nonlinear contraction type condition in ordered k metric spaces the presented results generalize and extend the very recent results of choudhury and metiya b s choudhury and n metiya the point of coincidence and common fixed point for a pair of mappings in cone metric spaces computers and mathematics with applications 60 2010 1686 1695

common fixed point theorems for contractive maps two common fixed point theorems have been proved by using minimal type commutativity and contractive conditions the last theorem extends known results on compatible maps to a wider class of mappings

cone metric spaces and fixed point theorems of contractive mappings in this paper we introduce cone metric spaces prove some fixed point theorems of contractive mappings on cone metric spaces

common fixed point theorems for ordered contractions and quasicontractions in ordered cone metric spaces in the first part of this paper we generalize results on common fixed points in ordered cone metric spaces obtained by i altun and g durmaz i altun g durmaz some fixed point theorems on ordered cone metric spaces rend circ mat palermo 58 2009 319 325 and i altun b damnjanovic and d djoric i altun b damnjanovic d djoric fixed point and common fixed point theorems on ordered cone metric spaces appl math lett 2009 doi 10 1016 j aml 2009 09 016 by weakening the respective contractive condition then the notions of quasicontraction and g quasicontraction are introduced in the setting of ordered cone metric spaces and respective common fixed point theorems are proved in such a way known results on quasicontractions and g quasicontractions in metric spaces and cone metric spaces are extended to the setting of ordered cone metric spaces examples show that there are cases when new results can be applied while old ones cannot

coherent states and annihilation creation operators associated with the irreducible unitary representations of su 1 1 we construct a kind of annihilation creation operators related to the affine coherent states next we re interpret them as annihilation creation operators associated with the irreducible unitary representation of the algebra su 1 1 by adding another generator to the two generators of the unitary representation of the one dimensional affine group

calcul fonctionnel par la transformation de mellin et operateurs admissibles mellin s transform is used to establish a functional calculus of a class of pseudodifferential operators depending on a small parameter h 0 we apply for exeample this result to prove the semi classical behaviour of the discrete spectrum of schrodinger operators h2 v and of dirac operators h j 13 jdj 4 v

common fixed points for g f type maps in cone metric spaces abstract in this paper we study common fixed points for the self and non self g f type maps in cone metric spaces our main results are related to the cases when g is f quasi contraction in a sense of das and naik and the cone need not be normal these results generalize several well known comparable results in the literature

approximation semi classique de l equation de heisenberg we study the semi classical approximation for the solution of heisenberg equation in terms of pseudo differential operators and establish a semi classical version of egorov s theorem as an application of these results we get the classical limit of quantum mechanical correlation functions for a class of non bounded observables

rhoades type fixed point theorems for a pair of nonself mappings abstract using suitable conditions of weak commutativity we prove theorems for a pair of nonself mappings which generalize earlier results due to rhoades and assad et al some illustrative examples and applications are also discussed

approximation of point of coincidence and common fixed points of quasi contraction mappings using the jungck iteration scheme let x d be a cone metric space over a solid vector space y in this paper we prove a convergence theorem with error estimates and localization formula for jungck iteration process for approximating points of coincidence and common fixed points of two selfmappings t and f of x satisfying a quasi contraction condition of the type d t x t y co d f x f y d f x t x d f y t y d f x t y d f y t x for all x y x where 0 1 is a constant our result complements the recent result of ding et al 9 the main result is new even in the classical metric space setting moreover this result answers an open question posed by olaleru 17 concerning common fixed points in metric spaces

invariant approximations and r subweakly commuting maps the existence of invariant approximations for r subweakly commuting mappings is proved our results extend most of the known results to a new class of noncommuting mappings

ordered cone metric spaces and fixed point results in this paper we introduce a partial order on a cone metric space and prove a caristi type theorem furthermore we prove fixed point theorems for single valued nondecreasing and weakly increasing mappings and multi valued mappings on an ordered cone metric space

hilbert spaces of analytic functions for the sl 2 r coherent states and a class of associated integral transforms it is shown that the bargmann segal hilbert spaces of entire analytic functions and bargmann s canonical hilbert spaces of functions analytic within the open unit disc are connected by simple integral transform pairs a further consequence of this analysis is the analog of the bargmann transform for the sl 2 r or su 1 1 group

common coupled fixed point theorems in cone metric spaces for w compatible mappings in this paper we introduce the concept of a w compatible mappings to obtain coupled coincidence point and coupled point of coincidence for nonlinear contractive mappings in cone metric space with a cone having non empty interior coupled common fixed point theorems for such mappings are also proved our results generalize extend and unify several well known comparable results in the literature results are supported by three examples

common fixed points under contractive conditions in cone metric spaces the aim of this paper is to present coincidence point result for two mappings in cone metric space which satisfy new contractive conditions our results generalize fixed point theorems of jungck g jungck commuting maps and fixed points amer math monthly 83 1976 261 263 abbas jungck m abbas g jungck common fixed point results for noncommuting mappings without continuity in cone metric spaces j math anal appl 341 2008 416 420 and fisher b fisher four mappings with a common fixed point arabic summary j univ kuwait sci 8 1981 131 139 in cone metric spaces to symmetric spaces

coherent states of su l 1 groups this work can be considered as a continuation of our previous study in which an explicit form of coherent states cs for all su n groups was constructed by means of representations on polynomials here we extend that approach to any su l 1 group and construct explicitly corresponding cs the cs are parametrized by dots of a coset space which is in that particular case the open complex ball cdl this space together with the projective space cpl which parametrizes the cs of the su l 1 group exhaust all complex spaces of constant curvature thus both sets of cs provide a possibility for an explicit analysis of the quantization problem on all the spaces of constant curvature this is why the cs of the su n and su l 1 groups are of importance in connection with quantization theory the constructed cs form an overcompleted system in the representation space and as quantum states possessing a minimum uncertainty they minimize an invariant dispersion of the quadratic casimir operator the classical limit is investigated in terms of symbols of operators the limit of the so called star commutator of the symbols generates the poisson bracket in cdl the latter plays the role of the phase space for the corresponding classical mechanics

a common fixed point theorem for r weakly commuting mappings in probabilistic spaces with nonlinear contractive conditions abstract this paper presents a common fixed point theorem for a family of r weakly commuting mappings satisfying nonlinear type contractive conditions this result improves and unifies previous results due to o regan and saadati d o regan r saadati nonlinear contraction theorems in probabilistic spaces appl math comput 195 2008 86 93 also the following results will be probabilistic versions and improvements of the results given in d w boyd j s w wong on nonlinear contractions proc am math soc 20 1969 458 464 g jungck commuting maps and fixed points am math month 83 1976 261 263 r p pant common fixed points of noncommuting mappings j math anal appl 188 1994 436 440 and many other

common fixed point theorems on generalized distance in ordered cone metric spaces in this paper we introduce a concept of the c distance in a cone metric space and by using the concept of the c distance prove some fixed point theorems in ordered cone metric spaces

su 1 1 barut girardello coherent states for landau levels it is shown that the hilbert space corresponding to all the quantum states of the landau problem can be split in two different ways as infinite direct sums of the finite and infinite dimensional representation subspaces of the lie algebras su 2 and su 1 1 with finite and infinite fold degeneracies respectively for each of the hilbert representation subspaces of the lie algebra su 1 1 we construct a suitable linear combination of its bases as the barut girardello coherent states

temporally stable coherent states for infinite well and poschl teller potentials this article is a direct illustration of a construction of coherent states which has been recently proposed by two of us jpg and jk we have chosen the example of a particle trapped in an infinite square well and also in poschl teller potentials of the trigonometric type in the construction of the corresponding coherent states we take advantage of the simplicity of the solutions which ultimately stems from the fact they share a common su 1 1 symmetry a la barut girardello many properties of these states are then studied both from mathematical and from physical points of view

common fixed point and approximation results for h operator pair with applications abstract the existence of common fixed point results for new classes of noncommuting selfmaps satisfying generalized i contraction or i nonexpansive type conditions is established as applications several invariant best approximation results are proved which unify extend and complement the well known results

a note on cone metric fixed point theory and its equivalence abstract the main aim of this paper is to investigate the equivalence of vectorial versions of fixed point theorems in generalized cone metric spaces and scalar versions of fixed point theorems in general metric spaces in usual sense we show that the banach contraction principles in general metric spaces and in t v s cone metric spaces are equivalent our theorems also extend some results in huang and zhang 2007 l g huang x zhang cone metric spaces and fixed point theorems of contractive mappings j math anal appl 332 2007 1468 1476 rezapour and hamlbarani 2008 sh rezapour r hamlbarani some notes on the paper cone metric spaces and fixed point theorems of contractive mappings j math anal appl 345 2008 719 724 and others

absence of singular continuous spectrum for certain self adjoint operators we give a sufficient condition for a self adjoint operator to have the following properties in a neighborhood of a pointe of its spectrum a its point spectrum is finite b its singular continuous spectrum is empty c its resolvent satisfies a class of a priori estimates

on common fixed points in g metric spaces using e a property in this paper we introduce some new types of pairs of mappings f g on g metric spaces called g weakly commuting of type g f and g r weakly commuting of type g f we obtain also several common fixed point results by using the e a property

maximal violation of bell inequalities for mixed states we show that mixed states can produce maximal violations in the bell inequality due to clauser horne shimony and holt chsh this follows from the degeneracy of the operator which is naturally associated with the bell inequality here called the bell operator we have calculated the form of all the eigenvalues for the generic chsh bell operator finally we consider several examples which demonstrate the utility of studying the eigenvalues and eigenvectors of the bell operator

coincidence and common fixed point results in partially ordered cone metric spaces and applications to integral equations abstract in this paper coincidence and common fixed point results are established in a partially ordered cone metric space an application of our results obtained to prove the existence of a common solution to integral equations is presented

quasi contraction of perov type abstract perov 1964 19 used the concept of vector valued metric space and obtained a banach type fixed point theorem on such a complete generalized metric space in this article we study fixed point results for the new extensions of ciric s quasi contraction to cone metric space and we give some generalized versions of the fixed point theorem of perov as corollaries we generalized some results of zima 1992 28 and borkowski et al 2010 4 for a banach space with a non normal cone the theory is illustrated with some examples

common fixed points for banach operator pairs in best approximation the notion of banach operator pairs is introduced as a new class of noncommuting maps some common fixed point theorems for banach operator pairs and the existence of the common fixed points of best approximation are presented these results are proved without the assumption of linearity or affinity for either f or g which shows that the concept about banach operator pairs is potentially useful in the study of common fixed points

on ciric maps with a generalized contractive iterate at a point and fisher s quasi contractions in cone metric spaces in this paper we generalize and unify some results of sehgal and guseman and ciric s theorem for mappings with a generalized contractive iterate at a point to cone metric spaces in which the cone does not need to be normal as corollaries we obtain recent results of huang and zhang and raja and vaezpour furthermore we introduce the definition of fisher quasi contractions on cone metric spaces and study their properties among other things using new method of proof we solve the open problem for the interval of contractive constant l of ciric quasi contraction in non normal cone metric spaces and as sn immediate corollary we recover the recent result of rezapour and hamlbarani

common fixed point results for noncommuting mappings without continuity in generalized metric spaces using the setting of a generalized metric space a fixed point theorem is proved for one map and several fixed point theorems are proved for two maps these results generalize several well known comparable results in the literature

common fixed point theorems of gregus type for weakly compatible mappings satisfying contractive conditions of integral type abstract we prove a common fixed point theorem of gregus type for four mappings satisfying a contractive condition of integral type in metric spaces using the concept of weak compatibility which generalizes theorem 2 of a djoudi l nisse gregus type fixed points for weakly compatible mappings bull belg math soc 10 2003 369 378 and other papers we prove also common fixed point theorems of gregus type using a strict contractive condition of integral type a property e a and a common property e a introduced by m aamri d el moutawakil some new common fixed point theorems under strict contractive conditions j math anal appl 270 2002 181 188 and w liu j wu z li common fixed points of single valued and multi valued maps int j math math sci 19 2005 3045 3055 respectively

generalized φ contraction for a pair of mappings on cone metric spaces using the setting of cone metric space a fixed point theorem is proved for two maps and several corollaries are obtained in these cases the cone does not need to be normal these results generalize several well known compatible recent and classical results in the literature as an application the existence of solution of an integral equation is presented

common fixed point results for noncommuting mappings without continuity in cone metric spaces the existence of coincidence points and common fixed points for mappings satisfying certain contractive conditions without appealing to continuity in a cone metric space is established these results generalize several well known comparable results in the literature

common fixed points for four maps in cone metric spaces the existence of coincidence points and common fixed points for four mappings satisfying generalized contractive conditions without exploiting the notion of continuity of any map involved therein in a cone metric space is proved these results extend unify and generalize several well known comparable results in the existing literature

on cone metric spaces a survey abstract using an old m krein s result and a result concerning symmetric spaces from s radenovic z kadelburg quasi contractions on symmetric and cone symmetric spaces banach j math anal 5 1 2011 38 50 we show in a very short way that all fixed point results in cone metric spaces obtained recently in which the assumption that the underlying cone is normal and solid is present can be reduced to the corresponding results in metric spaces on the other hand when we deal with non normal solid cones this is not possible in the recent paper m a khamsi remarks on cone metric spaces and fixed point theorems of contractive mappings fixed point theory appl 2010 7 pages article id 315398 doi 10 1115 2010 315398 the author claims that most of the cone fixed point results are merely copies of the classical ones and that any extension of known fixed point results to cone metric spaces is redundant also that underlying banach space and the associated cone subset are not necessary in fact khamsi s approach includes a small class of results and is very limited since it requires only normal cones so that all results with non normal cones which are proper extensions of the corresponding results for metric spaces cannot be dealt with by his approach

fixed point theorems in fuzzy metric spaces using property e a abstract we prove two common fixed point theorems for a pair of weakly compatible maps in fuzzy metric spaces both in the sense of kramosil and michalek and in the sense of george and veeramani by using e a property

coherent states for systems with discrete and continuous spectrum for a system with one degree of freedom coherent states that are parametrized by classical canonical action angle variables are introduced these states also possess continuity of labelling a resolution of unity and temporal stability the insistence on canonical action angle variables strongly restricts any remaining arbitrariness in the coherent state definition such states are introduced for semibounded hamiltonian operators having either a discrete or a continuous spectrum hamiltonians that have both discrete and continuous parts in their spectrum are also discussed

approximation of common fixed points of weakly compatible pairs using the jungck iteration abstract we show that the jungck iteration scheme can be used to approximate the common fixed points of some weakly compatible pairs of generalized quasicontractive operators defined on metric spaces the existence of coincidence points are also discussed for those pair of maps the results are generalizations of well known results of the convergence of picard iterations for single self maps of banach spaces in particular the results improve generalize and extend the recent results of berinde v berinde a common fixed point theorem for compatible quasi contractive self mappings in metric spaces applied mathematics and computation 213 2009 348 354 and answers the open question posed in the paper

time decay of scattering solutions and resolvent estimates for semiclassical schrodinger operators we study the semiclassical schrodinger operator h2 v x h 0 1 and establish various results on the time decay of scattering solutions and the semiclassical bounds for the powers of the resolvent for short range potentials the time decay results obtained in this paper are the best possible and this enables us to conclude the equivalence between the non trapping condition in classical mechanics and the uniform time decay of wave functions in quantum mechanics

fixed point theorems for families of weakly non expansive maps abstract in this paper we present some fixed point theorems for families of weakly non expansive maps under some relatively weaker and more general conditions our results generalize and improve several results due to jungck g jungck fixed points via a generalized local commutativity int j math math sci 25 8 2001 497 507 jachymski j jachymski a generalization of the theorem by rhoades and watson for contractive type mappings math japon 38 6 1993 1095 1102 guo c guo an extension of fixed point theorem of krasnoselski chinese j math p o c 21 1 1993 13 20 rhoades b e rhoades a comparison of various definitions of contractive mappings trans amer math soc 226 1977 257 290 and others

fixed point theorem for two non self mappings in cone metric spaces in this paper we extend a fixed point theorem of imdad and kumar for a pair of non self maps to non normal cone spaces

the clebsch gordan problem of the sl 2 r coherent states the clebsch gordan problems of the barut girardello and perelomov coherent states of sl 2 r are studied using the associated hilbert spaces as the respective carrier spaces of the representations of the group for the barut girardello coherent states this hilbert space is a subspace of the bargmann segal hilbert space b c2 called the reduced bargmann space the generators of the group in this realization are essentially the boson operators of holman and biedenharn which provide a convenient starting point of the problem for the perelomov coherent states the associated hilbert space turns out to be bargmann s canonical carrier space for the realization of the discrete series of representations namely the hilbert space of functions analytic inside the open unit disc the scalar product the principal vector and a complete orthonormal set in these hilbert spaces are constructed and used for the explicit evaluation of the clebsch gordan coefficients for each of the coherent state systems the produ

spherical harmonics coherent states constructed by the second lowest and second highest bases of su 1 1 lie algebra the second lowest and second highest bases of the discrete positive and negative irreducible representations of su 1 1 lie algebra via spherical harmonics are used to construct generalized coherent states depending on whether the representation label is an even or odd integer each of the new coherent states is separated into two different classes they are constituted by appropriate superpositions of the increasing and decreasing infinite sequences with respect to the m index of the spherical harmonics ym2j m m j 1 and ym2k m 1 m k 2 and converge to the known functions also the non oscillating measures to realize the resolution of the identity condition on the unit disk are calculated

abstract metric spaces and sehgal guseman type theorems recently raja and vaezpour p raja and s m vaezpour some extensions of banach s contraction principle in complete cone metric spaces fixed point theory appl 2008 11 pages doi 10 1155 2008 768294 article id 768294 proved some results for sehgal guseman type theorems in the framework of abstract cone metric spaces over a normal solid cone the purpose of this paper is to present this in the framework of symmetric spaces which are associated with abstract cone metric spaces introduced by radenovic and kadelburg s radenovic z kadelburg quasi contractions on symmetric and cone symmetric spaces isi j bjma electronic in press our results extend and generalize sehgal guseman type theorems from metric and abstract metric spaces to some symmetric spaces examples are given to illustrate the results

some common fixed point theorems for banach operator pairs with applications in best approximation abstract the ordered pair t i of two self maps of a metric space x d is called a banach operator pair if the set f i of fixed points of i is t invariant i e t f i f i some common fixed point theorems for a banach operator pair and the existence of common fixed points of best approximation are presented in this paper the results prove generalize and extend some results of al thagafi m a al thagafi common fixed points and best approximation j approx theory 85 1996 318 323 carbone a carbone applications of fixed point theorems jnanabha 19 1989 149 155 chen and li j chen z li common fixed points for banach operator pairs in best approximations j math anal appl 336 2007 1466 1475 habiniak l habiniak fixed point theorems and invariant approximation j approx theory 56 1989 241 244 jungck and sessa g jungck s sessa fixed point theorems in best approximation theory math japon 42 1995 249 252 sahab khan and sessa s a sahab m s khan s sessa a result in best approximation theory j approx theory 55 1988 349 351 shahzad n shahzad invariant approximations and r subweakly commuting maps j math anal appl 257 2001 39 45 and of few others

coincidence and fixed points for hybrid strict contractions abstract we define the property e a for single valued and multivalued mappings and introduce the notion of t weak commutativity for a hybrid pair f t of single valued and multivalued maps we obtain some coincidence and fixed point theorems for this class of maps and derive as application an approximation theorem

coincidence and fixed points in symmetric spaces under strict contractions abstract some common fixed point theorems due to aamri and el moutawakil m aamri d el moutawakil some new common fixed point theorems under strict contractive conditions j math anal appl 270 2002 181 188 and pant and pant r p pant v pant common fixed points under strict contractive conditions j math anal appl 248 2000 327 332 proved for strict contractive mappings in metric spaces are extended to symmetric semi metric spaces under tight conditions some related results are derived besides discussing illustrative examples which establish the utility of results proved in this note

semiclassical estimates on resolvents of schrodinger operators with homogeneous electric field abstract we are interested in the limiting absorption principle for schrodinger operators of the form h h h 2 x 1 v x 0 h h 0 for a large class of potentials v we establish various estimates for the resolvents of h h at non trapping energy the proof is based on a simple commutator technique our results seem to be new even in the case of h 1

spectral analysis of n body schrodinger operators for a large class of two body potentials we solve two of the main problems in the spectral analysis of multiparticle quantum hamiltonians explicitly we prove that the point spectrum lies in a closed countable set and describe that set in terms of the eigenvalues of hamiltonians of subsystems and that there is no singular continuous spectrum we accomplish this by extending mourre s work on three body problems to n body problems

coherent states on the m sheeted covering group of su 1 1 coherent states associated with the m sheeted covering group of su 1 1 are considered and such properties as overcompleteness and resolution of the identity are studied they are used to define analytic representations in which the transformations of the m sheeted covering group of su 1 1 are implemented as extended mobius conformal mappings applications of this formalism in the study of hamiltonians that describe m particle clustering are also considered

nonlinear ψ quasi contractions of ciric type in partial metric spaces abstract in this paper we obtain results of fixed and common fixed points for self mappings satisfying a nonlinear contractive condition of ciric type in the framework of partial metric spaces we also prove results of fixed point for self mappings satisfying an ordered nonlinear contractive condition in the setting of ordered partial metric spaces

banach operator pair and common fixed points for nonexpansive maps abstract let x be a normed space and t and i be two nonexpansive self maps on the closed convex subset c x it is proved that if i t is a banach operator pair and t c is compact then f i t 0 a family of nonexpansive maps is also investigated the well known de marr s fixed point theorem is extended to the noncommuting case by introducing a notion of banach operator family as an application of the theorem the problem for the common fixed point in invariant approximation for convex set is solved directly in a quite different way from the others before

common fixed point theorems for c distance in ordered cone metric spaces abstract recently cho et al y j cho r saadati s h wang common fixed point theorems on generalized distance in ordered cone metric spaces comput math appl 61 2011 1254 1260 introduced the concept of the c distance in a cone metric space and established some fixed point theorems on c distance the aim of this paper is to extend and generalize the main results of cho et al 20 and also show some examples to validate our main results

approximation of fixed points of uniformly r subweakly commuting mappings we introduce a new class of uniformly r subweakly commuting mappings and then using this class study the problem of approximation of common fixed points of asymptotically s nonexpansive mappings in a banach space with uniformly g teaux differentiable norm

new nonlinear coherent states based on hypergeometric type operators the main goal of this paper is to present an alternative method to construct new kinds of nonlinear coherent states to do this we first establish a class of hypergeometric type of generalized displacement operators 1fr 0 0 1 r 1 za act on the vacuum state of the harmonic oscillator and generate normalized quantum states of the fock space which admit a resolution of the identity through a positive definite measure on the complex plane furthermore realization of the compact form of these states as functions of the position coordinate x for r 2 leads to a generating function of the hermite polynomials in terms of the modified bessel function finally studying some statistical characters reveals that they have indeed non classical features such as squeezing an anti bunching effect and sub poissonian statistics too

a remarkable property of spherical harmonics it is shown that a certain bilinear expression on the space of spherical harmonics of equal angular momentum is constant on the two sphere

common fixed points for p operator pair with applications the existence of common fixed point results for new classes of noncommuting selfmaps satisfying generalized i contraction or i nonexpansive type conditions is established as applications several invariant best approximation results are proved which unify extend and complement the well known results

the point of coincidence and common fixed point for a pair of mappings in cone metric spaces in this paper the existence of a point of coincidence and a common fixed point for two weakly compatible maps on a cone metric space has been established the two mappings are assumed to satisfy certain weak inequalities supporting examples are also given

fixed point theory in cone metric spaces obtained via the scalarization method motivated by the scalarization method in vector optimization theory we take a new approach to fixed point theory on cone metric spaces by using our method we prove some fixed point theorems and several common fixed point theorems on cone metric spaces in which the cone need not be normal our results improve and generalize many well known results from the literature