\documentclass{amsart} % options include 12pt or 11pt or 10pt % classes include article, report, book, letter, thesis \usepackage{setspace} \usepackage{a4} \usepackage{amsthm} \usepackage{latexsym} \usepackage{amsfonts} \usepackage{graphicx} \usepackage{textcomp} \usepackage{cite} \usepackage{enumerate} \usepackage{amssymb} \usepackage{hyperref} \usepackage{amsmath} \usepackage{tikz} \usepackage[mathscr]{euscript} \usepackage{mathtools} \newtheorem{theorem}{Theorem}[section] \newtheorem{acknowledgement}[theorem]{Acknowledgement} \newtheorem{conjecture}[theorem]{Conjecture} \newtheorem{corollary}[theorem] {Corollary} \newtheorem{definition}[theorem]{Definition} \newtheorem{example}[theorem]{Example} \newtheorem{lemma} [theorem]{Lemma} \newtheorem{notation}[theorem]{Notation} \newtheorem{observation}[theorem]{Observation} \newtheorem{problem}[theorem]{Problem} \newtheorem{proposition}[theorem]{Proposition} \newtheorem{remark}[theorem]{Remark} \newtheorem{question}[theorem]{Question} \setlength{\parindent}{0pt} \setlength{\evensidemargin}{0.3cm} \setlength{\oddsidemargin}{0.3cm} \setlength{\topmargin}{-1cm} \textwidth 16cm \textheight 23cm \onehalfspacing \title{This is the title} \newcommand{\Cross}{\mathbin{\tikz [x=1.4eh,y=1.4eh,line width=.2ex] \draw (0,0) -- (1,1) (0,1) -- (1,0);}}% \raggedbottom \newcommand{\abs}[1]{\lvert#1\rvert} \newcommand{\blankbox}[2]{% \parbox{\columnwidth}{\centering \setlength{\fboxsep}{0pt}% \fbox{\raisebox{0pt}[#2]{\hspace{#1}}}% }% } \usepackage{fancyhdr} %\pagestyle{fancy} \pagestyle{fancy} %\thispagestyle{empty} \fancyhead[LO]{\textbf{Octonionic Heisenberg-Robertson-Schrodinger and Maccone-Pati Uncertainty Principles}} \fancyhead[RE]{\textbf{K. Mahesh Krishna}} \begin{document} \hrule\hrule\hrule\hrule\hrule \vspace{0.3cm} \begin{center} {\bf\large{{Octonionic Heisenberg-Robertson-Schrodinger and Maccone-Pati Uncertainty Principles}}}\\ \vspace{0.3cm} \hrule\hrule\hrule\hrule\hrule \vspace{0.3cm} \textbf{K. Mahesh Krishna}\\ School of Mathematics and Natural Sciences\\ Chanakya University Global Campus\\ NH-648, Haraluru Village\\ Devanahalli Taluk, Bengaluru North District\\ Karnataka State, 562 110, India\\ Email: kmaheshak@gmail.com\\ Date: \today \end{center} \hrule\hrule \vspace{0.5cm} %-------------------------------------- \textbf{Abstract}: Let $\mathcal{O}$ be an octonionic Hilbert space. Let $A: \mathcal{D}(A)\subseteq \mathcal{O}\to \mathcal{O}$ and $B:\mathcal{D}(B)\subseteq \mathcal{O}\to \mathcal{O}$ be possibly unbounded self-adjoint linear operators. Then for all $h \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\|h\|=1$, we show that \begin{align*} (1) \quad \quad \quad \Delta _h(A)\Delta _h(B)\geq \frac{\sqrt{|\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle|^2+|\langle [A,B]h, h \rangle |^2}}{2} \end{align*} and \begin{align*} (2) \quad \quad \quad \Delta _h(A)^2+ \Delta _h(B)^2 \geq \frac{|\langle (A+B)h, y \rangle|^2+|\langle (A-B)h, y \rangle|^2}{2}, \quad \forall y \in \mathcal{O} \text{ satisfying } \|y\|\leq1 \text{ and } \langle h, y \rangle =0, \end{align*} where $ \Delta _h(A)\coloneqq \|Ah-\langle Ah, h \rangle h \|$. We call Inequality (1) as octonionic Heisenberg-Robertson-Schrodinger uncertainty principle and Inequality (2) as octonionic Maccone-Pati uncertainty principle. \\ \textbf{Keywords}: Uncertainty principle, Octonionic Hilbert space.\\ \textbf{Mathematics Subject Classification (2020)}: 17A35, 46S10, 46C05.\\ \hrule %\tableofcontents \hrule \section{Introduction} Let $\mathcal{H}$ be a complex Hilbert space and $A$ be a possibly unbounded self-adjoint linear operator defined on the domain $\mathcal{D}(A)\subseteq \mathcal{H}$. For $h \in \mathcal{D}(A)$ with $\|h\|=1$, define the \textbf{uncertainty} or \textbf{variance} of $A$ at the point $h$ as \begin{align*} \Delta _h(A)\coloneqq \|Ah-\langle Ah, h \rangle h \|=\sqrt{\|Ah\|^2-\langle Ah, h \rangle^2}. \end{align*} In 1929, Robertson \cite{ROBERTSON} derived the following operator form of the uncertainty principle (also called as uncertainty relation or uncertainty inequality) by Heisenberg in 1927 \cite{HEISENBERG}. Recall that for two linear operators $A: \mathcal{D}(A)\subseteq \mathcal{H}\to \mathcal{H}$ and $B:\mathcal{D}(B)\subseteq \mathcal{H}\to \mathcal{H}$, we define the commutator $[A,B] \coloneqq AB-BA$ and the anti-commutator $\{A,B\}\coloneqq AB+BA$. \begin{theorem} \cite{ROBERTSON, HEISENBERG, VONNEUMANNBOOK, DEBNATHMIKUSINSKI} (\textbf{Heisenberg-Robertson Uncertainty Principle}) Let $A:\mathcal{D}(A)\subseteq \mathcal{H}\to \mathcal{H}$ and $B:\mathcal{D}(B)\subseteq \mathcal{H}\to \mathcal{H}$ be possibly unbounded self-adjoint linear operators. Then for all $h \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\|h\|=1$, we have \begin{align}\label{HR} \frac{1}{2} \left(\Delta _h(A)^2+ \Delta _h(B)^2\right)\geq \frac{1}{4} \left(\Delta _h(A)+ \Delta _h(B)\right)^2 \geq \Delta _h(A) \Delta _h(B) \geq \frac{1}{2}|\langle [A,B]h, h \rangle |. \end{align} \end{theorem} In 1930, Schrodinger improved Inequality (\ref{HR}) \cite{SCHRODINGER}. \begin{theorem} \cite{SCHRODINGER, BERTLMANNFRIIS} \label{SE} (\textbf{Heisenberg-Robertson-Schrodinger Uncertainty Principle}) Let $A: \mathcal{D}(A)\subseteq \mathcal{H}\to \mathcal{H}$ and $B: \mathcal{D}(B)\subseteq \mathcal{H}\to \mathcal{H}$ be possibly unbounded self-adjoint linear operators. Then for all $h \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\|h\|=1$, we have \begin{align*} \Delta _h(A) \Delta _h(B) &\geq |\langle Ah, Bh \rangle-\langle Ah, h \rangle \langle Bh, h \rangle|\\ &=\frac{\sqrt{|\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle|^2+|\langle [A,B]h, h \rangle |^2}}{2}\\ &=\frac{\sqrt{(\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle)^2-\langle [A,B]h, h \rangle ^2}}{2}. \end{align*} \end{theorem} In 2014, Maccone and Pati derived the following uncertainty principles which work for orthogonal vectors \cite{MACCONEPATI}. \begin{theorem} \cite{MACCONEPATI} (\textbf{Maccone-Pati Uncertainty Principles}) \label{MP} Let $A: \mathcal{D}(A)\subseteq \mathcal{H}\to \mathcal{H}$ and $B: \mathcal{D}(B)\subseteq \mathcal{H}\to \mathcal{H}$ be possibly unbounded self-adjoint linear operators. Then for all $h \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\|h\|=1$, we have \begin{enumerate}[\upshape(i)] \item \begin{align*} \Delta _h(A)^2+ \Delta _h(B)^2 &\geq|\langle (A+B)h, k \rangle|^2-\langle \{A,B\}h, h \rangle+2\langle Ah, h \rangle\langle Bh, h \rangle, \\ &\quad \forall k \in \mathcal{H} \text{ satisfying } \|k\|=1 \text{ and } \langle h, k \rangle =0. \end{align*} \item \begin{align*} \Delta _h(A)^2+ \Delta _h(B)^2 &\geq|\langle (A-B)h, k \rangle|^2+\langle \{A,B\}h, h \rangle-2\langle Ah, h \rangle\langle Bh, h \rangle, \\ &\quad \forall k \in \mathcal{H} \text{ satisfying } \|k\|=1 \text{ and } \langle h, k \rangle =0. \end{align*} \item \begin{align*} \Delta _h(A)^2+ \Delta _h(B)^2 \geq \frac{|\langle (A+B)h, k \rangle|^2+|\langle (A-B)h, k \rangle|^2}{2}, \quad \forall k \in \mathcal{H} \text{ satisfying } \|k\|=1 \text{ and } \langle h, k \rangle =0. \end{align*} \item \begin{align*} \Delta _h(A)\Delta _h(B) \geq \frac{2\langle Ah, h \rangle\langle Bh, h \rangle-\langle \{A,B\}h, h \rangle}{2-\left|\left\langle \left(\frac{A}{\Delta _h(A)}+\frac{B}{\Delta _h(B)}\right)h, k\right\rangle \right|^2}, \quad \forall k \in \mathcal{H} \text{ satisfying } \|k\|=1 \text{ and } \langle h, k \rangle =0. \end{align*} \item \begin{align*} \Delta _h(A)\Delta _h(B) \geq \frac{-2\langle Ah, h \rangle\langle Bh, h \rangle+\langle \{A,B\}h, h \rangle}{2-\left|\left\langle \left(\frac{A}{\Delta _h(A)}-\frac{B}{\Delta _h(B)}\right)h, k\right\rangle \right|^2}, \quad \forall k \in \mathcal{H} \text{ satisfying } \|k\|=1 \text{ and } \langle h, k \rangle =0. \end{align*} \end{enumerate} \end{theorem} We derive octonionic analogues of Theorem \ref{SE} in Theorem \ref{NH} and Theorem \ref{MP} in Theorem \ref{QMP}. We end the introduction by recalling the definition of octonionic Hilbert spaces. Let $\{e_j\}_{j=1}^7$ be the free symbols with multiplicative relations governed by the following table \cite{BAEZ}. \begin{table}[h!] \centering \renewcommand{\arraystretch}{1.3} \begin{tabular}{c|ccccccc} $\times$ & $e_1$ & $e_2$ & $e_3$ & $e_4$ & $e_5$ & $e_6$ & $e_7$ \\ \hline $e_1$ & $-1$ & $e_4$ & $e_7$ & $-e_2$ & $-e_6$ & $e_5$ & $-e_3$ \\ $e_2$ & $-e_4$ & $-1$ & $e_5$ & $e_1$ & $-e_3$ & $e_7$ & $-e_6$ \\ $e_3$ & $-e_7$ & $-e_5$ & $-1$ & $e_6$ & $e_2$ & $-e_4$ & $e_1$ \\ $e_4$ & $e_2$ & $-e_1$ & $-e_6$ & $-1$ & $e_7$ & $e_3$ & $-e_5$ \\ $e_5$ & $e_6$ & $e_3$ & $-e_2$ & $-e_7$ & $-1$ & $-e_1$ & $e_4$ \\ $e_6$ & $-e_5$ & $-e_7$ & $e_4$ & $-e_3$ & $e_1$ & $-1$ & $e_2$ \\ $e_7$ & $e_3$ & $e_6$ & $-e_1$ & $e_5$ & $-e_4$ & $-e_2$ & $-1$ \end{tabular} \end{table}\\ Let \begin{align*} \mathbb{O}\coloneqq \left\{a_0+\sum_{j=1}^{7}a_je_j: a_0, \dots, a_7 \in \mathbb{R} \right\} \end{align*} be the non-associative division algebra of octonion numbers with the conjugation \begin{align*} \overline{a_0+\sum_{j=1}^{7}a_je_j}\coloneqq a_0-\sum_{j=1}^{7}a_je_j, \quad \forall a_0+\sum_{j=1}^{7}a_je_j \in \mathbb{O} \end{align*} and the modulus \begin{align*} \left|a_0+\sum_{j=1}^{7}a_je_j\right|\coloneqq \sqrt{\sum_{j=0}^{7}a_j^2}, \quad \forall a_0+\sum_{j=1}^{7}a_je_j \in \mathbb{O}. \end{align*} \begin{definition}\cite{GOLDSTINEHORWITZ} A right octonionic vector space $\mathcal{O}$ over $\mathbb{O}$ is said to be a (right) \textbf{octonionic Hilbert space} if there exists a map (called as octonionic inner product) $ \langle \cdot, \cdot \rangle: \mathcal{O}\times \mathcal{O} \to \mathbb{O}$ such that the following hold. \begin{enumerate}[\upshape(i)] \item $\langle x, x \rangle \geq 0$, $\forall x \in \mathcal{O}$. If $x \in \mathcal{O}$ satisfies $\langle x, x \rangle =0 $, then $x=0$. \item $\langle x+y, z \rangle =\langle x, z \rangle+\langle y, z \rangle$, $\forall x,y,z \in \mathcal{O}$. \item $\operatorname{Re}(\langle x, yq \rangle) =\operatorname{Re}(\langle x, y \rangle q)$, $\forall x,y \in \mathcal{O}$, $\forall q \in \mathbb{O}$. \item $\langle x, yr \rangle =\langle x, y \rangle r$, $\forall x,y \in \mathcal{O}$, $\forall r \in \mathbb{R}$. \item $\langle x, xq \rangle =\langle x, x \rangle q$, $\forall x \in \mathcal{O}$, $\forall q \in \mathbb{O}$. \item $\langle x, y \rangle=\overline{\langle y,x \rangle}$, $\forall x,y \in \mathcal{O}$. \item $\mathcal{O}$ is complete w.r.t. the norm $\|x\|\coloneqq \sqrt{\langle x, x \rangle}$, $\forall x \in \mathcal{O}$. \end{enumerate} \end{definition} \section{Octonionic Heisenberg-Robertson-Schrodinger Uncertainty Principle} In this article, $\mathcal{O}$ denotes a right octonionic Hilbert space. Throughout the entire paper, given $x \in \mathcal{O}$ and a $r \in \mathbb{R}\setminus \{0\}$, the expression $x/r$ denotes $x r^{-1}$. Note that this is meaningful only for division by non-zero real numbers and not for arbitrary octonions, since the octonions are not commutative. Let $\mathcal{O}$ be an octonionic Hilbert space and $A$ be a possibly unbounded self-adjoint linear operator defined on domain $\mathcal{D}(A)\subseteq \mathcal{O}$. For $h \in \mathcal{D}(A)$ with $\|h\| =1$, we define the \textbf{uncertainty} or \textbf{variance} of $A$ at the point $h$ as \begin{align*} \Delta _h(A)\coloneqq \|Ah-\langle Ah, h \rangle h \|=\sqrt{\|Ah\|^2-\langle Ah, h \rangle^2}. \end{align*} Note that $\langle Ah, h \rangle \in \mathbb{R}$. For two maps $A: \mathcal{D}(A)\subseteq \mathcal{O}\to \mathcal{O}$ and $B: \mathcal{D}(B)\subseteq \mathcal{O}\to \mathcal{O}$, we define the commutator $[A,B] \coloneqq AB-BA$ and the anti-commutator $\{A,B\}\coloneqq AB+BA$. \begin{theorem} (\textbf{Octonionic Heisenberg-Robertson-Schrodinger Uncertainty Principles})\label{NH} Let $\mathcal{O}$ be an octonionic Hilbert space. Let $A: \mathcal{D}(A)\subseteq \mathcal{O}\to \mathcal{O}$ and $B: \mathcal{D}(B)\subseteq \mathcal{O}\to \mathcal{O}$ be possibly unbounded self-adjoint linear operators. Then for all $h \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\|h\|=1$, we have \begin{enumerate}[\upshape(i)] \item \begin{align*} \Delta _h(A)\Delta_h(B)\geq\frac{|\langle [A,B]h,h \rangle|}{2}. \end{align*} \item \begin{align*} \Delta _h(A)\Delta_h(B)\geq \frac{|\langle \{A,B\}h,h \rangle -2\langle Ah, h \rangle \langle Bh, h \rangle|}{2}. \end{align*} \item \begin{align*} \Delta _h(A)\Delta _h(B)&\geq \frac{\sqrt{|(\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle)^2-\langle [A,B]h, h \rangle ^2|}}{2}\\ &=\frac{\sqrt{|\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle|^2+|\langle [A,B]h, h \rangle |^2}}{2}. \end{align*} \end{enumerate} \end{theorem} \begin{proof} Let $h \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ be such that $\|h\|=1$. Since $A$ and $B$ are self-adjoint, we first make an important observation: $\langle Ah, h \rangle,\langle Bh, h \rangle \in \mathbb{R}$. \begin{enumerate}[\upshape(i)] \item \begin{align*} \Delta _h(A)\Delta _h(B)&\geq\langle Ah -\langle Ah, h \rangle h, Bh -\langle Bh, h \rangle h\rangle\\ &= |\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle|\\ &\geq \frac{|\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle-\overline{\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle}|}{2}\\ &=\frac{|\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle-\langle Bh, Ah \rangle+\langle Bh, h \rangle\langle Ah, h \rangle|}{2}\\ &=\frac{|\langle BAh, h \rangle-\langle ABh, h \rangle|}{2}\\ &=\frac{|-\langle (AB-BA)h,h \rangle |}{2}\\ &=\frac{|\langle [A,B]h,h \rangle|}{2}. \end{align*} \item \begin{align*} \Delta _h(A)\Delta _h(B)&\geq\langle Ah -\langle Ah, h \rangle h, Bh -\langle Bh, h \rangle h\rangle\\ &= |\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle|\\ &\geq \frac{|\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle+\overline{\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle}|}{2}\\ &=\frac{|\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle+\langle Bh, Ah \rangle-\langle Bh, h \rangle\langle Ah, h \rangle|}{2}\\ &=\frac{|\langle BAh, h \rangle-\langle Ah, h \rangle\langle Bh, h \rangle+\langle ABh, h \rangle-\langle Bh, h \rangle\langle Ah, h \rangle|}{2}\\ &=\frac{|\langle (AB+BA)h,h \rangle - 2\langle Ah, h \rangle\langle Bh, h \rangle|}{2}\\ &=\frac{|\langle \{A,B\}h,h \rangle -2\langle Ah, h \rangle \langle Bh, h \rangle|}{2}. \end{align*} \item Define \begin{align*} z\coloneqq Ah -\langle Ah, h \rangle h, \quad w\coloneqq Bh -\langle Bh, h \rangle h. \end{align*} Then \begin{align*} \langle z, w\rangle+ \langle w, z\rangle&=\langle Ah -\langle Ah, h \rangle h, Bh -\langle Bh, h \rangle h\rangle+\langle Bh -\langle Bh, h \rangle h, Ah -\langle Ah, h \rangle h\rangle\\ &=\langle BAh, h \rangle-\langle Ah, h \rangle\langle Bh, h \rangle+\langle ABh, h \rangle-\langle Bh, h \rangle\langle Ah, h \rangle\\ &=\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle \end{align*} and \begin{align*} \langle z, w\rangle- \langle w, z\rangle&=\langle Ah -\langle Ah, h \rangle h, Bh -\langle Bh, h \rangle h\rangle-\langle Bh -\langle Bh, h \rangle h, Ah -\langle Ah, h \rangle h\rangle\\ &=\langle BAh, h \rangle-\langle Ah, h \rangle\langle Bh, h \rangle-\langle ABh, h \rangle+\langle Bh, h \rangle\langle Ah, h \rangle\\ &=-\langle [A,B]h, h \rangle. \end{align*} Therefore \begin{align*} &\Delta _h(A)^2\Delta_h(B)^2+\Delta _h(B)^2\Delta_h(A)^2\geq |\langle z, w\rangle|^2+|\langle w, z\rangle|^2\\ &=\frac{(\langle z, w\rangle+ \langle w, z\rangle)^2-(\langle z, w\rangle- \langle w, z\rangle)^2}{2}\\ &=\frac{(\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle)^2-\langle [A,B]h, h \rangle^2}{2}. \end{align*} Note that \begin{align*} \overline{\langle [A,B]h, h \rangle }=-\langle [A,B]h, h \rangle \end{align*} and \begin{align*} \overline{\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle}=\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle. \end{align*} Therefore \begin{align*} -\langle [A,B]h, h \rangle ^2=|\langle [A,B]h, h \rangle |^2 \end{align*} and \begin{align*} (\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle)^2=|\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, h \rangle|^2. \end{align*} \end{enumerate} \end{proof} \section{Octonionic Maccone-Pati Uncertainty Principles} Here we derive octonionic Maccone-Pati uncertainty principles. \begin{theorem} (\textbf{Octonionic Maccone-Pati Uncertainty Principles}) \label{QMP} Let $\mathcal{O}$ be an octonionic Hilbert space. Let $A: \mathcal{D}(A)\subseteq \mathcal{O}\to \mathcal{O}$ and $B: \mathcal{D}(B)\subseteq \mathcal{O}\to \mathcal{O}$ be possibly unbounded self-adjoint linear operators. Then for all $h \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\|h\|=1$, we have \begin{enumerate}[\upshape(i)] \item \begin{align*} \Delta _h(A)^2+ \Delta _h(B)^2 &\geq|\langle (A+B)h, y \rangle|^2-\langle \{A,B\}h, h \rangle+2\langle Ah, h \rangle\langle Bh, h \rangle, \\ &\quad \forall y \in \mathcal{O} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle h,y \rangle =0. \end{align*} \item \begin{align*} \Delta _h(A)^2+ \Delta _h(B)^2 &\geq|\langle (A-B)h, y \rangle|^2+\langle \{A,B\}h, h \rangle-2\langle Ah, h \rangle\langle Bh, h \rangle, \\ &\quad \forall y \in \mathcal{O} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle h,y \rangle =0. \end{align*} \item \begin{align*} \Delta _h(A)^2+ \Delta _h(B)^2 \geq \frac{|\langle (A+B)h, y \rangle|^2+|\langle (A-B)h, y \rangle|^2}{2}, \quad \forall y \in \mathcal{O} \text{ satisfying } \|y\|\leq1 \text{ and } \langle h, y \rangle =0. \end{align*} \item \begin{align*} \Delta _h(A)\Delta _h(B) \geq \frac{2\langle Ah, h \rangle\langle Bh, h \rangle-\langle \{A,B\}h, h \rangle}{2-\left|\left\langle \left(\frac{A}{\Delta _h(A)}+\frac{B}{\Delta _h(B)}\right)h, y\right\rangle \right|^2}, \quad \forall y \in \mathcal{O} \text{ satisfying } \|y\|\leq1 \text{ and } \langle h,y \rangle =0. \end{align*} \item \begin{align*} \Delta _h(A)\Delta _h(B) \geq \frac{-2\langle Ah, h \rangle\langle Bh, h \rangle+\langle \{A,B\}h,h \rangle}{2-\left|\left\langle \left(\frac{A}{\Delta _h(A)}-\frac{B}{\Delta _h(B)}\right)h, y\right\rangle \right|^2}, \quad \forall y \in \mathcal{O} \text{ satisfying } \|y\|\leq1\text{ and } \langle h, y \rangle =0. \end{align*} \end{enumerate} \end{theorem} \begin{proof} Let $h \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\|h\|=1$. Let $y \in \mathcal{O}$ be such that $ \|y\|\leq 1 $ and $ \langle h,y \rangle =0.$ \begin{enumerate}[\upshape(i)] \item \begin{align*} &|\langle (A+B)h, y \rangle|^2=|\langle Ah-\langle Ah, h \rangle h+Bh-\langle Bh, h \rangle h, y \rangle|^2\\ &\leq \|y\|^2\langle (Ah-\langle Ah, h \rangle h)+ (Bh-\langle Bh, h \rangle h), (Ah-\langle Ah, h \rangle h)+ (Bh-\langle Bh, h \rangle h)\rangle\\ &\leq \langle Ah-\langle Ah, h \rangle h, Ah-\langle Ah, h \rangle h\rangle +\langle Bh-\langle Bh, h \rangle h, Bh-\langle Bh, h \rangle h\rangle \\ &\quad +\langle Bh-\langle Bh, h \rangle h, Ah-\langle Ah, h \rangle h\rangle+\langle Ah-\langle Ah, h \rangle h, Bh-\langle Bh, h \rangle h\rangle\\ &=\Delta_h(A)^2+\Delta_h(B)^2+\langle Bh, Ah \rangle -\langle Bh, h \rangle\langle Ah, h \rangle+\langle Ah, Bh \rangle -\langle Ah, h \rangle\langle Bh, h \rangle\\ &=\Delta_h(A)^2+\Delta_h(B)^2+\langle \{A,B\}h, h \rangle -2\langle Ah, h \rangle \langle Bh, h \rangle. \end{align*} \item Similar to (i). \item We get by adding (i) and (ii). \item \begin{align*} &\left|\left\langle \left(\frac{A}{\Delta_h(A)}+\frac{B}{\Delta_h(B)}\right)h, y\right \rangle \right|^2=\left|\left\langle \frac{Ah-\langle Ah, h \rangle h}{\Delta_h(A)}+\frac{Bh-\langle Bh, h \rangle h}{\Delta_h(B)}, y\right \rangle \right|^2\\ &\leq \|y\|^2\left\langle \frac{Ah-\langle Ah, h \rangle h}{\Delta_h(A)}+\frac{Bh-\langle Bh, h \rangle h}{\Delta_h(B)}, \frac{Ah-\langle Ah, h \rangle h}{\Delta_h(A)}+\frac{Bh-\langle Bh, h \rangle h}{\Delta_h(B)}\right \rangle\\ &\leq \left\langle \frac{Ah-\langle Ah, h \rangle h}{\Delta_h(A)}, \frac{Ah-\langle Ah, h \rangle h}{\Delta_h(A)}\right \rangle+\left\langle \frac{Bh-\langle Bh, h \rangle h}{\Delta_h(B)}, \frac{Bh-\langle Bh, h \rangle h}{\Delta_h(B)}\right \rangle\\ &\quad +\left\langle \frac{Bh-\langle Bh, h \rangle h}{\Delta_h(B)}, \frac{Ah-\langle Ah, h \rangle h}{\Delta_h(A)}\right \rangle+\left\langle \frac{Ah-\langle Ah, h \rangle h}{\Delta_h(A)}, \frac{Bh-\langle Bh, h \rangle h}{\Delta_h(B)}\right \rangle\\ &=1+1+\frac{\langle Bh, Ah \rangle-\langle Bh, h \rangle\langle Ah, h \rangle}{\Delta_h(A)\Delta_h(B)}+\frac{\langle Ah, Bh \rangle-\langle Ah, h \rangle\langle Bh, h \rangle}{\Delta_h(A)\Delta_h(B)}\\ &=2+\frac{-2\langle Ah, h \rangle\langle Bh, h \rangle +\langle \{A,B\}h, h \rangle}{\Delta_h(A)\Delta_h(B)}. \end{align*} Therefore \begin{align*} &-\frac{-2\langle Ah, h \rangle\langle Bh, h \rangle +\langle \{A,B\}h, h \rangle}{\Delta_h(A)\Delta_h(B)}\leq 2-\left|\left\langle \left(\frac{A}{\Delta_h(A)}+\frac{B}{\Delta_h(B)}\right)h, y\right \rangle \right|^2\\ &\implies \frac{2\langle Ah, h \rangle\langle Bh, h \rangle -\langle \{A,B\}h, h \rangle}{2-\left|\left\langle \left(\frac{A}{\Delta_h(A)}+\frac{B}{\Delta_h(B)}\right)h, y\right \rangle \right|^2}\leq \Delta_h(A)\Delta_h(B). \end{align*} \item Similar to (iv). \end{enumerate} \end{proof} \section{Acknowledgments} AI is used for the literature survey and grammar improvement. \bibliographystyle{plain} \begin{thebibliography}{1} \bibitem{BAEZ} John~C. Baez. \newblock The octonions. \newblock {\em Bull. Am. Math. Soc., New Ser.}, 39(2):145--205, 2002. \bibitem{BERTLMANNFRIIS} Reinhold~A Bertlmann and Nicolai Friis. \newblock {\em Modern Quantum Theory: From Quantum Mechanics to Entanglement and Quantum Information}. \newblock Oxford University Press, 2023. \bibitem{DEBNATHMIKUSINSKI} Lokenath Debnath and Piotr Mikusi\'{n}ski. \newblock {\em Introduction to {H}ilbert spaces with applications}. \newblock Academic Press, Inc., San Diego, CA, 1999. \bibitem{GOLDSTINEHORWITZ} H.~H. Goldstine and L.~P. Horwitz. \newblock Hilbert space with non-associative scalars. {I}. \newblock {\em Math. Ann.}, 154:1--27, 1964. \bibitem{HEISENBERG} W.~Heisenberg. \newblock The physical content of quantum kinematics and mechanics. \newblock In {\em Quantum Theory and Measurement}, pages 62--84. Princeton University Press, Princeton, NJ, 1983. \bibitem{MACCONEPATI} Lorenzo Maccone and Arun~K. Pati. \newblock Stronger uncertainty relations for all incompatible observables. \newblock {\em Phys. Rev. Lett.}, 113(26):260401, 2014. \bibitem{ROBERTSON} H.~P. Robertson. \newblock The uncertainty principle. \newblock {\em Phys. Rev.}, 34(1):163--164, 1929. \bibitem{SCHRODINGER} E.~Schr\"{o}dinger. \newblock About {H}eisenberg uncertainty relation. \newblock {\em Bulgar. J. Phys.}, 26(5-6):193--203, 1999. \bibitem{VONNEUMANNBOOK} John von Neumann. \newblock {\em Mathematical foundations of quantum mechanics}. \newblock Princeton University Press, Princeton, NJ, 2018. \end{thebibliography} \end{document}