In this paper, we use a modification of Krasnoselskii’s fixed point theorem introduced by Burton (see [Burton, T. A.: Liapunov functionals, fixed points and stability by Krasnoseskii’s theorem. Nonlinear Stud., 9 (2002), 181–190.] Theorem 3) to obtain stability results of the zero solution of the totally nonlinear neutral differential equation with variable delay $$x^{\text{'}}\left(t\right)=-a\left(t\right)h\left(x\left(t\right)\right)+\frac{d}{dt}Q\left(t,x\left(t-\tau \left(t\right)\right)\right)+G\left(t,x\left(t\right),x\left(t-\tau \left(t\right)\right)\right).$$ The stability of the zero solution of this eqution provided that $h\left(0\right)=Q\left(t,0\right)=G\left(t,0,0\right)=0$. The Caratheodory condition is used for the functions...

This Note is the continuation of a previous paper with the same title. Here (Part II) we show that for every choice of the sequence $u{}_a(\cdot )$, ${\mathrm{\Sigma }}_a$'s trajectory $l_a$ after the instant $d+\eta a$ tends in a certain natural sense, as $a\to \mathrm{\infty }$, to a certain geodesic $l$ of $V_d$, with origin at $\left(\overline{q},\overline{u}\right)$. Incidentally $l$ is independent of the choice of applied forces in a neighbourhood of $\left(\overline{q},\overline{u}\right)$ arbitrarily prefixed.

Let p > 3 be a prime, and let Rₚ be the set of rational numbers whose denominator is not divisible by p. Let Pₙ(x) be the Legendre polynomials. In this paper we mainly show that for m,n,t ∈ Rₚ with m≢ 0 (mod p), $P_{[p/6]}\left(t\right)\equiv -(3/p){\sum }_{x=0}^{p-1}((x³-3x+2t)/p)\left(modp\right)$ and $\left({\sum }_{x=0}^{p-1}((x³+mx+n)/p)\right)²\equiv ((-3m)/p){\sum }_{k=0}^{[p/6]}\left(\genfrac{}{}{0pt}{}{2k}{k}\right)\left(\genfrac{}{}{0pt}{}{3k}{k}\right)\left(\genfrac{}{}{0pt}{}{6k}{3k}\right){((4m³+27n²)/\left(12³·4m³\right))}^k\left(modp\right)$, where (a/p) is the Legendre symbol and [x] is the greatest integer function. As an application we solve some conjectures of Z. W. Sun and the author concerning ${\sum }_{k=0}^{p-1}\left(\genfrac{}{}{0pt}{}{2k}{k}\right)\left(\genfrac{}{}{0pt}{}{3k}{k}\right)\left(\genfrac{}{}{0pt}{}{6k}{3k}\right)/m^k\left(modp²\right)$, where m is an integer not divisible by p.

Let $x=x_0{x}_1\cdots$ be a fixed point of a substitution on the alphabet $\left\{a,b\right\},$ and let $U_a=\left(\begin{array}{cc}\hfill -1& \hfill -1\\ \hfill 0& \hfill 1\end{array}\right)$ and $U_b=\left(\begin{array}{cc}\hfill 1& \hfill 1\\ \hfill 0& \hfill 1\end{array}\right)$. We give a complete classification of the substitutions $\sigma :{\left\{a,b\right\}}^{☆}$ according to whether the sequence of matrices ${\left(U_{x_0}{U}_{x_1}\cdots U_{x_n}\right)}_{n=0}^{\infty }$ is bounded or unbounded. This corresponds to the boundedness or unboundedness of the oriented walks generated by the substitutions.

Fueter's result (see [6,8]) on inducing quaternionic regular functions from holomorphic functions of a complex variable is extended to Euclidean spaces ${\mathbb{R}}^{n+1}$. It is then proved to be consistent with M. Sce's generalization for $n$ being odd integers [6].

We consider a class of stationary viscous Hamilton-Jacobi equations aswhere $\lambda \ge 0$, $A\left(x\right)$ is a bounded and uniformly elliptic matrix and $H(x,\xi )$ is convex in $\xi$ and grows at most like ${\left|\xi \right|}^q+f\left(x\right)$, with $1\<q\<2$ and $f\in L^{N/q^{\text{'}}}\left(\Omega \right)$. Under such growth conditions solutions are in general unbounded, and there is not uniqueness of usual weak solutions. We prove that uniqueness holds in the restricted class of solutions satisfying a suitable energy-type estimate, ${(1+|u\left|\right)}^{\overline{q}-1}u\in H_0^1\left(\Omega \right)$, for a certain (optimal) exponent $\overline{q}$. This completes the...