How to make cooperation the optimizing strategy in a two‐person game

This paper demonstrates the existence of a partial tit‐for‐tat (matching) strategy which, when used by one player in an iterated “Prisoner's Dilemma” game, will induce a response of pure cooperation in the other player if that player behaves optimally. The minimum matching frequency of such a strategy is shown to be monotonically related to the Rapoport‐Chammah “Cooperation Index.”     

Properties of solutions of two second-order differential equations with the Painlevé property

Theoretical and Mathematical Physics - We consider a Hamiltonian system equivalent to the Painlevé II equation with respect to one component and to the Painlevé XXXIV equation with...     

New equilibria for noncooperative two‐person games

New equilibrium concepts for noncooperative two‐person games are introduced and examined. Although these equilibria coincide with the Nash equilibria in all constant‐sum games, they differ significantly in other cases. In particular, for finite repetitions of the prisoner's dilemma, some cooperating strategy combinations become equilibria.     

On the ε-entropy of classes of holomorphic functions

Suppose thatB _R ^d is a ball of radiusR in ℂ ^d and σ is the standard measure on the unit sphere in ℂ ^d . ForR>1, 1≤p≤∞, and for the natural numbersl, d, byH _R ⁰ (l, p, d) we denote the class of functionsf holomorphic inB _R ^d and such that in the homogeneous polynomial expansion of the firstl summands the zero and radial derivatives of orderl belong to the closed unit ball of the Hardy spaceH ^p (B _R ^d ). In this paper an asymptotic formula for the ε-entropy of the classH _R ⁰ (l, p, d) in the spacesL ^p (σ), 1≤p<∞, and is obtained. Translated fromMatematicheskie Zametki, Vol. 68, No. 2, pp. 286–293, August, 2000.     

Stability on a cone in terms of two measures for impulsive differential equations with “supremum”

The stability of nonlinear impulsive differential equations with “supremum” is studied. A special type of stability, combining two different measures and a dot product, is defined. The definition is a generalization of several types of stability known in the literature. Razumikhin’s method as well as a comparison method for scalar impulsive ordinary differential equations have been employed.     

The Π-strategy in a differential game with linear control constraints

The concept of a linear constraint on the controls of the players in a differential game of pursuit, which, in a certain sense, generalizes both integral and geometrical constraints, is introduced. The optimal parallel pursuit strategy (Π-strategy) is constructed for the corresponding problem.     

A feedback nash equilibrium solution for non–cooperative innovations in a stochastic differential game framework

In this paper, a stochastic model of non–cooperative technological innovations is developed. A feedback Sash equilibrium solution is obtained and the equilibrium innovation strategies are derived in explicit form. Several interesting properties of the equilibrium strategies are observed. On the one hand, an increase in the degree of competition in the industry, in the discount rate or in the state of technologyreduces innovation efforts. On the other hand, an increases the rate of degradation of the state of technology due to obsolescence results in an increase in innovation investment. While an increase in uncertainty reduces the expected present value of present and future discounted profits innovation efforts increase as uncertainty increases     

A note on the differential forms of ε(∞) space

This short note intends to show how to carry over some of the most elementary concepts of differential geometry to fractal-like ε^(∞) spaces.     

Properties for a Class of Holomorphic Mapson Hilbert Space

Itiswell-knownthattheanalyticfunctionwithpositiverealpartintheunitdiscofthecomplexplaneplaysaveryimportantroleinthegeometrictheoryofcomplexvariablefunc-tions.Ithasbeenremarkablehowtoextendtheclassicalresultofthetheoryoffunctionstoabstractspacesinrecentyears[2].Inthisnotewedefineageneralizedhalf-planeinHilbertspaceandfindthebiholomorphicmapoftheunitballonHilbertspaceontothishalf-plane.Asacorollary,wegiveashortproofofaresultin[5].UsingtheaboveholomooorphicmapweobtainthedistortiontheoremandPick…     

Properties of two Shannon’s ciphers

In 1949 Shannon published the famous paper “Communication theory of secrecy systems” where he briefly described two ciphers, but did not investigate their properties. In this note we carry out information-theoretical analysis of these ciphers. In particular, we propose estimations of the cipher equivocation and the probability of correct deciphering without key.     

Bang–bang-type Nash equilibrium point for Markovian nonzero-sum stochastic differential game

In this Note, we solve a nonzero-sum stochastic differential game (NZSDG) with bang–bang-type equilibrium controls by using backward stochastic differential equations (BSDEs). The generator is multi-dimensional and discontinuous with respect to z.     

Asymptotics of multipoint Hermite–Padé approximants of the first type for two beta functions

Mathematical Notes - The asymptotic behavior of the Hermite–Padé approximants of the first type for two beta functions are studied. The results are expressed in terms of equilibrium...     

Kolmogorov ε-entropy of attractor for a non-autonomous strongly damped wave equation

In this paper, we study the long-time behavior of solutions for a non-autonomous strongly damped wave equation. We first prove the existence of a uniform attractor for the equation with a translation compact driving force and then obtain an upper estimate for the Kolmogorov ε-entropy of the uniform attractor. Finally we obtain an upper bound of the fractal dimension of the uniform attractor with quasiperiodic force.     

Scales of ε-uniform a priori estimates for nonstationary convection-dominated diffusion problems

Convection-diffusion problems of practical interest are often convection-dominated in the sense that the diffusion parameter ε satisfies 0<ε≪1. Standard error estimates for numerical approximations of such problems mostly contain constants which depend either reciprocally on ε or at least on higher order norms of the solution. These norms possibly increase to infinity in the hyperbolic limit ε→0. For the Lagrange-Galerkin scheme such error estimates have been proven by Douglas and Russell, Pironneau or Süli. In the particular case of the Navier-Stokes equations Johnson, Rannacher and Boman have observed that some of those constants which arise in existing analyses depend exponentially on the Reynolds number. Consequently, standard error analyses have no real meaning in the case of convection-dominance. Recently, Bause and Knabner have developed a rigorous ε-uniform convergence theory for finite element and Lagrange-Galerkin approximations of convection-dominated diffusion problems. The error analysis is heavily based on ε-uniform a priori estimates for the solution of the continuous problems. In their work such ε-uniform estimates are established in the Sobolev spacesL ²(Ω) andH ²(Ω) in a Lagrangian framework by transforming the convection-diffusion problem into subcharacteristic coordinates. To obtain the ε-uniformH ²-bound, strong conditions about the right-hand side which cannot realistically be assumed in practice are supposed. In this paper we demonstrate how the method of complex interpolation of Banach spaces can be employed to derive elegantly ε-uniform a priori estimates in intermediate Sobolev spaces of fractional order. We will observe that in particularH ^α-regularity of the data has to be supposed to get an ε-uniformH ^α-bound for the solution. To derive the desired estimates we use several complex interpolation results which we provide first.

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Sunto I problemi di convezione-diffusione di interesse applicativo sono spesso convezione-dominati, nel senso che il parametro di diffusione ε soddisfa 0<ε≪1. Le stime standard dell’errore nelle approssimazioni numeriche di tali problemi generalmente contengono costanti che dipendono o reciprocamente da ε o almeno da norme più elevate della soluzione. Queste norme possono tendere all’infinito nel limite iperbolico ε→0. Queste stime sono state determinate, per lo schema di Lagrange-Galerkin, da Douglas e Russell, Pironneau o Süli. Nel caso particolare delle equazioni di Navier-Stokes, Johnson, Rannacher e Boman hanno osservato che alcune di queste costanti dipendono esponenzialmente dal numero di Reynolds. Di conseguenza, l’analisi standard dell’errore non è significativa nel caso di dominanza della convezione. Recentemente, Bause e Knabner hanno sviluppato una teoria rigorosa della ε-convergenza per le approssimazioni agli elementi una teoria rigorosa della ε-convergenza per le approssimazioni agli elementi finite e per quelle di Lagrange-Galerkin relativamente a problemi di diffusione convezione-dominati. l’analisi dell’errore è pesantemente basata su stime a priori ε-uniformi per la soluzione dei problemi continui. In quel lavoro, tali stime sono stabilite negli spazi di SobolevL ²(Ω) eH ²(Ω) in rappresentazione Lagrangiana trasformando il problema di convezione-diffusione in coordinate sub-caratteristiche. Per ottenere la stima ε-uniforme inH ²(Ω), si fanno delle ipotesi stringenti sul secondo membro le quali possono non essere realisticamente assunte nella pratica. In questo lavoro mostriamo come il metodo dell’interpolazione complessa degli spazi di Banach possa essere usato per ottenere eleganti stime a priori ε-uniformi in spazi di Sobolev ad esponente frazionario. In particolare, osserveremo che per ottenere una stima ε-uniforme inH ^α per la soluzione occorre assumereH ^α regolarità sui dati. Per derivare le stime desiderate facciamo uso di diversi risultati di interpolazione complessa che vengono forniti.

     

A canonical system of two differential equations with periodic coefficients and the Poincaré-Denjoy theory of differential equations on a torus

The passage from Cartesian to polar coordinates in a canonical system with periodic coefficients gives rise to a nonlinear differential equation whose right-hand side is periodic in time and the polar angle and thus this equation can be regarded as a differential equation on a torus. In accord with Poincaré-Denjoy theory, the behavior of a solution to a differential equation on a torus is characterized by the rotation number and some homeomorphic mapping of a circle onto itself. We study connections of strong stability (instability) of a canonical system, including the membership in the nth stability (instability) domain, with the rotation number and fixed points of this mapping.     

Properties of (θ,s)-continuous functions

Joseph and Kwack [Proc. Amer. Math. Soc. 80 (1980) 341–348] introduced the notion of (θ,s)-continuous functions in order to investigate S-closed spaces due to Thompson [Proc. Amer. Math. Soc. 60 (1976) 335–338]. In this paper, further properties of (θ,s)-continuous functions are obtained and relationships between (θ,s)-continuity, contra-continuity and regular set-connectedness defined by Dontchev et al. [Internat. J. Math. Math. Sci. 19 (1996) 303–310 and elsewhere] are investigated.     

Diagonally implicit Runge—Kutta methods for differential algebraic equations of indices two and three

Diagonally implicit Runge-Kutta methods satisfying additional order conditions are examined. These conditions make it possible to solve differential algebraic equations of indices two and three to higher accuracy. Advantages of the proposed methods over other known techniques are demonstrated using test problems.