%------------------------------------------------------------------------------ % Beginning of journal.tex %------------------------------------------------------------------------------ % \documentclass[12pt, reqno]{amsart} \usepackage{amsmath, amsthm, amscd, amsfonts, amssymb, graphicx, color} \usepackage[bookmarksnumbered, plainpages, backref]{hyperref} \textheight 22.5truecm \textwidth 14.5truecm \setlength{\oddsidemargin}{0.35in}\setlength{\evensidemargin}{0.35in} \setlength{\topmargin}{-.5cm} \newtheorem{theorem}{Theorem}[section] \newtheorem{lemma}[theorem]{Lemma} \newtheorem{proposition}[theorem]{Proposition} \newtheorem{corollary}[theorem]{Corollary} \theoremstyle{definition} \newtheorem{definition}[theorem]{Definition} \newtheorem{example}[theorem]{Example} \newtheorem{xca}[theorem]{Exercise} \newtheorem{problem}[theorem]{Problem} \theoremstyle{remark} \newtheorem{remark}[theorem]{Remark} \numberwithin{equation}{section} \begin{document} \setcounter{page}{1} %\noindent\parbox{2.85cm}{\includegraphics*[keepaspectratio=true,scale=1.75]{BJMA.jpg}} \noindent\parbox{4.85in}{\hspace{0.1mm}\\[1.5cm]\noindent \textcolor{green}{J. Nonlinear Sci. Appl. 0 (0000), no. 0, 00--00}\\ $\frac{\rule{6.55in}{0.05in}}{{}}$\\ {\footnotesize \textcolor{red}{\textsc{\textbf{\large{T}}he \textbf{\large{J}}ournal of \textbf{\large{N}}onlinear \textbf{\large{S}}ciences \text{and} \textbf{\large{A}}pplications}}\\ %ISSN: 1110-111x (electronic)\\ \textcolor[rgb]{0.00,0.00,0.84}{\textbf{http://www.tjnsa.com }}\\ $\frac{{}}{\rule{6.55in}{0.05in}}$}\\[.5in]} \title[Short Title]{Title of Paper} \author[F. Author, S. Author]{First Author$^1$ and Second Author$^2$$^{*}$} \address{$^{1}$ Department of Mathematics, Shomal University, P. O. Box 731, Amol, Iran.} \email{\textcolor[rgb]{0.00,0.00,0.84}{first@shomal.ac.ir}} \address{$^{2}$ Department of Mathematics, Shomal University, P. O. Box 731, Amol, Iran.; \newline Amirkabir University} \email{\textcolor[rgb]{0.00,0.00,0.84}{second@shomal.ac.ir}} \dedicatory{This paper is dedicated to Professor ABCD} \subjclass[2000]{Primary 39B82; Secondary 44B20, 46C05.} \keywords{Convexity, Stability, functional equation, Hahn-Banach theorem.} \date{Received: 2 March 2006; Revised: 15 August 15. \newline \indent $^{*}$ Corresponding author} \begin{abstract} The abstract should be informative, precise and not exceed 150 words. \end{abstract} \maketitle \section{Introduction and preliminaries} \noindent Here you should state the introduction, preliminaries and your notation. Authors are required to state clearly the contribution of the paper and its significance in the introduction. There should be some survey of relevant literature. \subsection{Instructions for author(s)} Manuscripts should be typeset in English with double spacing by using AMS-LaTex. The authors are encouraged to use the TJNSA The abstract should not exceed 150 words. The authors should include as footnotes for the first page, Keywords and Phrases as well as 2000 Mathematics Subject Classifications. Other footnotes may also be included in the first page about supporting grants, presentations, etc. `References' should be listed in alphabetical order according to the surnames of the first author at the end of the paper and should be cited in the text as, \cite{M-M, RAS} or \cite[Theorem 4.1]{MUR}. \section{Main results} The following is an example of a definition. \begin{definition} Let ${\mathcal X}$ be a real or complex linear space. A mapping $\| \cdot \| :{\mathcal X}\rightarrow \left[ 0,\infty \right) $ is called a $2$-norm on ${\mathcal X}$\ if it satisfies the following conditions: \begin{enumerate} \item $\| x\| =0\Leftrightarrow x=0,$ \item $\| \lambda x\| =\| \lambda \| \| x\| \ \ $for all $x\in {\mathcal X}$ and all scalar $\lambda ,$ \item $\| x+y\| ^{2}\leq 2\left( \| x\| ^{2}+\| y\| ^{2}\right) \ $for all $x,y\in {\mathcal X}.$ \end{enumerate} \end{definition} %---------------------------------------------------------------------------------------% Here is an example of a table. \begin{table}[ht] \caption{}\label{eqtable} \renewcommand\arraystretch{1.5} \noindent\[ \begin{array}{|c|c|c|} \hline 1&2&3\\ \hline f(x)&g(x)&h(x)\\ \hline a&b&c\\ \hline \end{array} \] \end{table} The following is an example of an example. %---------------------------------------------------------------------------------------% \begin{example} Let ${\mathcal A}$ be a unital algebra, let $a_{0}$ be a central element of ${\mathcal A}$ with $a_{0}^{n}=a_{0}$ for some natural number $n$, and let $\theta:{\mathcal A}\to {\mathcal A}$ be a homomorphism. Define $\varphi:{\mathcal A}\to {\mathcal A}$ by $\varphi(a)=a_{0}\theta(a)$. Then we have \begin{eqnarray*} \varphi(a_{1}\ldots a_{n})&=&a_{0}\theta(a_{1}\ldots a_{n})\\ &=& a_{0}^{n}\theta(a_{1})\ldots\theta(a_{n})\\ &=& a_{0}\theta(a_{1})\ldots a_{0}\theta(a_{n})\\ &=& \varphi(a_{1})\ldots\varphi(a_{n}). \end{eqnarray*} Hence $\varphi$ is an $n$-homomorphism. \end{example} %---------------------------------------------------------------------------------------% The following is an example of a theorem and a proof. %---------------------------------------------------------------------------------------% \begin{theorem}\label{main} If ${\bf B}$ is an open ball of a real inner product space ${\mathcal X}$ of dimension greater than $1$, ${\mathcal Y}$ is a real sequentially complete linear topological space, and $f: {\bf B}\setminus\{0\} \to {\mathcal Y}$ is orthogonally generalized Jensen mapping with parameters $s=t>\frac{1}{\sqrt{2}} \, r$, then there exist additive mappings $T: {\mathcal X}\to {\mathcal Y}$ and $b:{\mathbb R}_+\to {\mathcal Y}$ such that $f(x) = T(x) + b\left (\|x\|^2\right )$ for all $x\in {\bf B}\setminus \{0\}$. \end{theorem} %---------------------------------------------------------------------------------------% \begin{proof} First note that if $f$ is a generalized Jensen mapping with parameters $t=s \geq r $, then \begin{eqnarray}\label{additive} \begin{split} f(\lambda(x+y))&=\lambda f(x) + \lambda f(y)\\ &\leq \lambda (f(x) + f(y))\\ &= f(x) + f(y) \end{split} \end{eqnarray} for some $\lambda \geq 1$ and all $x, y\in {\bf B}\setminus \{0\}$ such that $x \perp y$. \medskip \noindent \underline{\rm Step (I)- the case that f is odd:} Let $x \in {\bf B} \setminus \{0\}$. There exists $y_0 \in {\bf B} \setminus \{0\}$ such that $x \perp y_0$, $x + y_0 \perp x - y_0$. We have \begin{eqnarray*} f(x)&=& f(x)- \lambda\, f\left ( \frac{x+y_0}{2\, \lambda}\, \right ) - \lambda \, f\left ( \frac{x-y_0}{2\, \lambda}\, \right )\\ &&+ \, \lambda \, f\left ( \frac{x+y_0}{2\, \lambda}\, \right ) - \lambda^2\, f\left ( \frac{x}{2\, \lambda^2}\, \right ) - \lambda^2 \, f\left ( \frac{y_0}{2\, \lambda^2}\, \right )\\ &&+ \, \lambda \, f\left ( \frac{x-y_0}{2\, \lambda}\, \right ) - \lambda^2 f\left ( \frac{x}{2\, \lambda^2}\, \right ) - \lambda^2\, f\left ( \frac{-y_0}{2\, \lambda^2}\, \right )\\ &&+\, 2\, \lambda^2 \, f\left (\frac{x}{2\, \lambda^2}\, \right )\\ &=& 2\, \lambda^2 \, f\left ( \frac{x}{2\, \lambda^2}\, \right ). \end{eqnarray*} \medskip \noindent \underline{\rm Step (II)- the case that f is even:} Using the same notation and the same reasoning as in the proof of Theorem \ref{main}, one can show that $f(x)=f(y_0)$ and the mapping $Q: {\mathcal X}\to {\mathcal Y}$ defined by $Q(x) : = (4\lambda^2)^n f((2\lambda^2)^{-n}x)$ is even orthogonally additive. \medskip Now the result can be deduced from Steps (I) and (II) and (\ref{additive}). \end{proof} %---------------------------------------------------------------------------------------% The following is an example of a remark. %---------------------------------------------------------------------------------------% \begin{remark} One can easily conclude that $g$ is continuous by using Theorem \ref{main}. \end{remark} %---------------------------------------------------------------------------------------% {\bf Acknowledgements:} Acknowledgements could be placed at the end of the text but precede the references. \bibliographystyle{amsplain} \begin{thebibliography}{10} \bibitem{MUR} G.J. Murphy, \textit{$C^*$-Algebras and Operator Theory}, Academic Press, Boston, 1990. \bibitem{M-M} M. Mirzavaziri and M.S. Moslehian, \textit{Automatic continuity of $\sigma$-derivations in $C^*$-algebras}, Proc. Amer. Math. Soc. \textbf{134} (2006), 3319--3327. \bibitem{RAS} Th.M. Rassias, \textit{Stability of the generalized orthogonality functional equation}, Inner product spaces and applications, 219--240, Pitman Res. Notes Math. Ser., 376, Longman, Harlow, 1997. \end{thebibliography} \end{document} %------------------------------------------------------------------------------ % End of journal.tex %------------------------------------------------------------------------------