Functional BES equation

Functional BES equation

We give a realization of the Beisert, Eden and Staudacher equation for the planar N = 4 supersymetric gauge theory which seems to be particularly useful to study the strong coupling limit. We are using a linearized version of the BES equation as two coupled equations involving an auxiliary density function. We write these equations in terms of the resolvents and we transform them into to a syst...

(BES Collaboration) †

BES data on J/ψ → γ(KK Sπ) are presented. There is a strong peak due to η(1440)/ι, which is fitted with a Breit-Wigner amplitude with s-dependent widths for decays to KK, κK, ηππ and ρρ; κ refers to the Kπ S-wave. At a KK̄π mass of ∼ 2040 MeV, there is a second peak with width ∼ 400 MeV; J = 0 is preferred over 1 and 2 respectively by 5.2 and 6.8 standard deviations. It is a possible candidate f...

On Hilbert Golab-Schinzel type functional equation

Let $X$ be a vector space over a field $K$ of real or complex numbers. We will prove the superstability of the following Go{l}c{a}b-Schinzel type equation$$f(x+g(x)y)=f(x)f(y), x,yin X,$$where $f,g:Xrightarrow K$ are unknown functions (satisfying some assumptions). Then we generalize the superstability result for this equation with values in the field of complex numbers to the case of an arbitr...

Hyers-Ulam Stability of Fibonacci Functional Equation

stability of the quadratic functional equation

In the present paper a solution of the generalizedquadratic functional equation$$f(kx+ y)+f(kx+sigma(y))=2k^{2}f(x)+2f(y),phantom{+} x,yin{E}$$ isgiven where $sigma$ is an involution of the normed space $E$ and$k$ is a fixed positive integer. Furthermore we investigate theHyers-Ulam-Rassias stability of the functional equation. TheHyers-Ulam stability on unbounded domains is also studied.Applic...