\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=1.4ex,y=1.4ex,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{Noncommutative Maccone-Pati Uncertainty Principles}} \fancyhead[RE]{\textbf{K. Mahesh Krishna}} \begin{document} \hrule\hrule\hrule\hrule\hrule \vspace{0.3cm} \begin{center} {\bf\large{{Noncommutative 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 $\mathcal{E}$ be a Hilbert C*-module over a unital C*-algebra $\mathcal{A}$. Let $A: \mathcal{D}(A) \subseteq \mathcal{E} \to \mathcal{E}$ and $B: \mathcal{D}(B)\subseteq \mathcal{E}\to \mathcal{E}$ be possibly unbounded self-adjoint morphisms. Then for all $x \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\langle x, x \rangle =1$, we show that \begin{align*} (1) \quad\quad\quad d_x(A)^2+d_x(B)^2&\geq \mp \langle \{A,B\}x, x \rangle +\langle (A\pm B)x, y \rangle\langle y, (A\pm B)x \rangle\pm \{\langle Ax, x \rangle, \langle Bx, x \rangle\}, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0 \end{align*} \begin{align*} (2) \quad \quad \quad d_x(A)^2+d_x(B)^2&\geq \mp i\langle [A,B]x, x \rangle +\langle (A\pm iB)x, y \rangle\langle y, (A\pm iB)x \rangle \mp i[\langle Ax, x \rangle, \langle Bx, x \rangle], \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} where \begin{align*} & d_x(A):= \sqrt{\langle Ax, Ax \rangle -\langle Ax, x \rangle^2},\quad [A,B] := AB-BA, \\ & [\langle Ax, x \rangle,\langle Bx, x \rangle]:= \langle Ax, x \rangle\langle Bx, x \rangle -\langle Bx, x \rangle\langle Ax, x \rangle. \end{align*} We call Inequalities (1) and (2) as noncommutative Maccone-Pati uncertainty principles. They reduce to uncertainty principles derived by Maccone and Pati [\textit{Phys. Rev. Lett., 2014}] whenever $\mathcal{A}=\mathbb{C}$. \textbf{Keywords}: Uncertainty Principle, Hilbert C*-module. \textbf{Mathematics Subject Classification (2020)}: 46L08.\\ \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 domain $\mathcal{D}(A)\subseteq \mathcal{H}$. For $h \in \mathcal{D}(A)$ with $\|h\|=1$, define the \textbf{uncertainty} 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 mathematical form of the uncertainty principle of Heisenberg derived 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 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 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 \{A,B\}h, h \rangle -2\langle Ah, h \rangle\langle Bh, 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 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)^2+ \Delta _h(B)^2 \geq-i\langle [A,B]h, h \rangle +|\langle (A+iB)h, k \rangle|^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)^2+ \Delta _h(B)^2 \geq i\langle [A,B]h, h \rangle +|\langle (A-iB)h, k \rangle|^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)^2+ \Delta _h(B)^2 \geq \frac{|\langle (A+iB)h, k \rangle|^2+|\langle (A-iB)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{-i\langle [A,B]h, h \rangle}{2-\left|\left\langle \left(\frac{A}{\Delta _h(A)}+i\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{i\langle [A,B]h, h \rangle}{2-\left|\left\langle \left(\frac{A}{\Delta _h(A)}-i\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*} \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 ask: What is noncommutative analogues of Theorems \ref{MP}? For this, we need the notion of noncommutative Hilbert spaces known as Hilbert C*-modules which are first introduced by Kaplansky \cite{KAPLANSKY} for modules over commutative C*-algebras and later developed for modules over arbitrary C*-algebras by Paschke \cite{PASCHKE} and Rieffel \cite{RIEFFEL}. Idea behind Hilbert C*-modules is simple: replace the field of complex numbers in the theory of Hilbert spaces by C*-algebras. Now the positive numbers are replaced by positive elements in C*-algebras. Hilbert C*-modules play an essential role in operator algebras, K-theory, KK-theory, operator spaces, quantum group theory, Morita equivalence, AW*-algebras, operator K-theory, group representation theory etc. We refer monographs \cite{MANUILOVTROITSKY, WEGGEOLSEN, THOMSEN, LANCE} for the beautiful use of Hilbert C*-modules in these areas. \begin{definition}\cite{KAPLANSKY, PASCHKE, RIEFFEL} Let $\mathcal{A}$ be a unital C*-algebra. A left module $\mathcal{E}$ over $\mathcal{A}$ is said to be a (left) \textbf{Hilbert C*-module} if there exists a map $ \langle \cdot, \cdot \rangle: \mathcal{E}\times \mathcal{E} \to \mathcal{A}$ such that the following conditions hold. \begin{enumerate}[\upshape(i)] \item $\langle x, x \rangle \geq 0$, $\forall x \in \mathcal{E}$. If $x \in \mathcal{E}$ satisfies $\langle x, x \rangle =0 $, then $x=0$. \item $\langle ax+y, z \rangle =a\langle x, z \rangle+\langle y, z \rangle$, $\forall x,y,z \in \mathcal{E}$, $\forall a \in \mathcal{A}$. \item $\langle x, y \rangle=\langle y,x \rangle^*$, $\forall x,y \in \mathcal{E}$. \item $\mathcal{E}$ is complete w.r.t. the norm $\|x\|\coloneqq \sqrt{\|\langle x, x \rangle\|}$, $\forall x \in \mathcal{E}$. \end{enumerate} \end{definition} In the paper, we use the following noncommutative Cauchy-Schwarz inequality. \begin{theorem}\cite{PASCHKE, RIEFFEL} \label{NCS} Let $\mathcal{E}$ be a Hilbert C*-module. Then \begin{align*} \langle x, y \rangle \langle y, x \rangle \leq \| \langle y, y \rangle \| \langle x, x \rangle , \quad \forall x, y \in \mathcal{E}. \end{align*} \end{theorem} Note that, eventhough we use Theorem \ref{NCS}, there are other variations of noncommutative Cauchy-Schwarz inequality, see \cite{BELLOMONTE, FUJIIFUJIIMOSLEHIANSEO, ARAMBASICBAKICMOSLEHIAN, ILLSEVICVAROSANEC}. We derive noncommutative analogues of Theorem \ref{MP} in Theorem \ref{NMP}. \section{Noncommutative Maccone-Pati Uncertainty Principles} Let $\mathcal{E}$ be a Hilbert C*-module over a unital C*-algebra $\mathcal{A}$ and $A$ be a possibly unbounded self-adjoint morphism defined on domain $\mathcal{D}(A)\subseteq \mathcal{E}$. For $x \in \mathcal{D}(A)$ with $\langle x, x\rangle =1$, we define the noncommutative uncertainty of $A$ at the point $x$ as \begin{align*} \Delta _x(A)\coloneqq \|Ax-\langle Ax, x \rangle x \|=\sqrt{\|\langle Ax, Ax \rangle -\langle Ax, x \rangle^2\|}. \end{align*} We define \begin{align*} d_x(A)\coloneqq \sqrt{\langle Ax, Ax \rangle -\langle Ax, x \rangle^2}=\sqrt{\langle Ax -\langle Ax, x \rangle x, Ax -\langle Ax, x \rangle x\rangle}. \end{align*} Then $d_x(A)\in \mathcal{A}$ and \begin{align*} \Delta _x(A)=\| d_x(A)\|. \end{align*} Given two elements $a, b \in \mathcal{A}$, we define $[a,b]\coloneqq ab-ba$ and $\{a,b\}\coloneqq ab+ba$. Similarly, for two morphisms $A: \mathcal{D}(A)\subseteq \mathcal{E}\to \mathcal{E}$ and $B: \mathcal{D}(B)\subseteq \mathcal{E}\to \mathcal{E}$, we define $[A,B] \coloneqq AB-BA$ and $\{A,B\}\coloneqq AB+BA$. \begin{theorem} (\textbf{Noncommutative Maccone-Pati Uncertainty Principles}) \label{NMP} Let $\mathcal{E}$ be a Hilbert C*-module over a unital C*-algebra $\mathcal{A}$. Let $A: \mathcal{D}(A)\subseteq \mathcal{E}\to \mathcal{E}$ and $B: \mathcal{D}(B)\subseteq \mathcal{E}\to \mathcal{E}$ be self-adjoint morphisms. Then for all $x \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\langle x, x \rangle =1$, we have \begin{enumerate}[\upshape(i)] \item \begin{align*} d_x(A)^2+d_x(B)^2&\geq -\langle \{A,B\}x, x \rangle +\langle (A+B)x, y \rangle\langle y, (A+B)x \rangle+\{\langle Ax, x \rangle, \langle Bx, x \rangle\}, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \|-\langle \{A,B\}x, x \rangle +\langle (A+B)x, y \rangle\langle y, (A+B)x \rangle+\{\langle Ax, x \rangle, \langle Bx, x \rangle\}\|, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} d_x(A)^2+d_x(B)^2&\geq \langle \{A,B\}x, x \rangle +\langle (A-B)x, y \rangle\langle y, (A-B)x \rangle-\{\langle Ax, x \rangle, \langle Bx, x \rangle\}, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \|\langle \{A,B\}x, x \rangle +\langle (A-B)x, y \rangle\langle y, (A-B)x \rangle-\{\langle Ax, x \rangle, \langle Bx, x \rangle\}\|, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} d_x(A)^2+d_x(B)^2&\geq \frac{\langle (A+B)x, y \rangle\langle y, (A+B)x \rangle+\langle (A-B)x, y \rangle\langle y, (A-B)x \rangle}{2}, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta _x(A)^2+\Delta _x(B)^2&\geq \frac{\|\langle (A+B)x, y \rangle\langle y, (A+B)x \rangle+\langle (A-B)x, y \rangle\langle y, (A-B)x \rangle\|}{2}, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} d_x(A)^2+d_x(B)^2&\geq -i\langle [A,B]x, x \rangle +\langle (A+iB)x, y \rangle\langle y, (A+iB)x \rangle-i[\langle Ax, x \rangle, \langle Bx, x \rangle], \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \|-i\langle [A,B]x, x \rangle +\langle (A+iB)x, y \rangle\langle y, (A+iB)x \rangle-i[\langle Ax, x \rangle, \langle Bx, x \rangle]\|, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} d_x(A)^2+d_x(B)^2&\geq i\langle [A,B]x, x \rangle +\langle (A-iB)x, y \rangle\langle y, (A-iB)x \rangle+i[\langle Ax, x \rangle, \langle Bx, x \rangle], \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \|i\langle [A,B]x, x \rangle +\langle (A-iB)x, y \rangle\langle y, (A-iB)x \rangle+i[\langle Ax, x \rangle, \langle Bx, x \rangle]\|, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} d_x(A)^2+d_x(B)^2&\geq \frac{\langle (A+iB)x, y \rangle\langle y, (A+iB)x \rangle+\langle (A-iB)x, y \rangle\langle y, (A-iB)x \rangle}{2}, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \frac{\|\langle (A+iB)x, y \rangle\langle y, (A+iB)x \rangle+\langle (A-iB)x, y \rangle\langle y, (A-iB)x \rangle\|}{2}, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \end{enumerate} \end{theorem} \begin{proof} Let $x \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\langle x, x \rangle =1$. Let $y \in \mathcal{E}$ be such that $ \|y\|\leq 1 $ and $ \langle x,y \rangle =0.$ \begin{enumerate}[\upshape(i)] \item \begin{align*} &\langle (A+B)x, y \rangle \langle y, (A+B)x \rangle\\ &=\langle Ax-\langle Ax, x \rangle x+Bx-\langle Bx, x \rangle x, y \rangle\langle y, Ax-\langle Ax, x \rangle x+Bx-\langle Bx, x \rangle x\rangle\\ &\leq \| \langle y, y \rangle \|\langle (Ax-\langle Ax, x \rangle x)+ (Bx-\langle Bx, x \rangle x), (Ax-\langle Ax, x \rangle x)+ (Bx-\langle Bx, x \rangle x)\rangle\\ &\leq \langle Ax-\langle Ax, x \rangle x, Ax-\langle Ax, x \rangle x\rangle +\langle Bx-\langle Bx, x \rangle x, Bx-\langle Bx, x \rangle x\rangle \\ &\quad +\langle Bx-\langle Bx, x \rangle x, Ax-\langle Ax, x \rangle x\rangle+\langle Ax-\langle Ax, x \rangle x, Bx-\langle Bx, x \rangle x\rangle\\ &=d_x(A)^2+d_x(B)^2+\langle Bx, Ax \rangle -\langle Bx, x \rangle\langle Ax, x \rangle+\langle Ax, Bx \rangle -\langle Ax, x \rangle\langle Bx, x \rangle\\ &=d_x(A)^2+d_x(B)^2+\langle \{A,B\}x, x \rangle -\{\langle Ax, x \rangle, \langle Bx, x \rangle\}. \end{align*} Therefore \begin{align*} d_x(A)^2+d_x(B)^2\geq -\langle \{A,B\}x, x \rangle +\langle (A+B)x, y \rangle\langle y, (A+B)x \rangle+\{\langle Ax, x \rangle, \langle Bx, x \rangle\}. \end{align*} \item Take norm on (i). \item Similar to (i). \item Take norm on (iii). \item \begin{align*} &\langle (A+B)x, y \rangle \langle y, (A+B)x \rangle+\langle (A-B)x, y \rangle \langle y, (A-B)x \rangle=2\langle Ax, y \rangle \langle y, Ax \rangle +2\langle Bx, y \rangle \langle y, Bx \rangle\\ &=2\langle Ax-\langle Ax, x \rangle x, y \rangle \langle y, Ax-\langle Ax, x \rangle x \rangle +2\langle Bx-\langle Bx, x \rangle x, y \rangle \langle y, Bx-\langle Bx, x \rangle x\rangle\\ &\leq 2\|\langle y, y \rangle \|\langle Ax-\langle Ax,x \rangle x, Ax-\langle Ax, x \rangle x \rangle + 2\|\langle y, y \rangle \|\langle Bx-\langle Bx,x \rangle x, Bx-\langle Bx, x \rangle x \rangle\\ &\leq 2d_x(A)^2+2d_x(B)^2. \end{align*} \item Take norm on (v). \item \begin{align*} &\langle (A+iB)x, y \rangle\langle y, (A+iB)x \rangle= \langle Ax+iBx, y \rangle\langle y, Ax+iBx \rangle\\ &= \langle Ax-\langle Ax, x \rangle x+i(Bx-\langle Bx, x \rangle x), y \rangle\langle y, Ax-\langle Ax, x \rangle x+i(Bx-\langle Bx, x \rangle x)\rangle\\ &\leq \| \langle y, y \rangle \|\langle (Ax-\langle Ax, x \rangle x)+i (Bx-\langle Bx, x \rangle x), (Ax-\langle Ax, x \rangle x)+i (Bx-\langle Bx, x \rangle x)\rangle\\ &\leq \langle Ax-\langle Ax, x \rangle x, Ax-\langle Ax, x \rangle x\rangle +\langle Bx-\langle Bx, x \rangle x, Bx-\langle Bx, x \rangle x\rangle \\ &\quad +i\langle Bx-\langle Bx, x \rangle x, Ax-\langle Ax, x \rangle x\rangle-i\langle Ax-\langle Ax, x \rangle x, Bx-\langle Bx, x \rangle x\rangle\\ &=d_x(A)^2+d_x(B)^2+i(\langle Bx, Ax \rangle -\langle Bx, x \rangle\langle Ax, x \rangle)-i(\langle Ax, Bx \rangle -\langle Ax, x \rangle\langle Bx, x \rangle)\\ &=d_x(A)^2+d_x(B)^2+i\langle [A,B]x, x \rangle +i[\langle Ax, x \rangle, \langle Bx, x \rangle]. \end{align*} Therefore \begin{align*} d_x(A)^2+d_x(B)^2\geq -i\langle [A,B]x, x \rangle +\langle (A+iB)x, y \rangle\langle y, (A+iB)x \rangle-i[\langle Ax, x \rangle, \langle Bx, x \rangle]. \end{align*} \item Take norm on (vii). \item Similar to (vii). \item Take norm on (ix). \item Add (vii) and (ix). \item Add (viii) and (ix), then take norm. \end{enumerate} \end{proof} \begin{corollary} Let $\mathcal{E}$ be a Hilbert C*-module over a unital commutative C*-algebra $\mathcal{A}$. Let $A:\mathcal{D}(A)\to \mathcal{E}$ and $B: \mathcal{D}(B)\to \mathcal{E}$ be self-adjoint morphisms. Then for all $x \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\langle x, x \rangle =1$, we have \begin{enumerate}[\upshape(i)] \item If $\mathcal{A}$ is commutative, then \begin{align*} d_x(A)^2+d_x(B)^2&\geq -i\langle [A,B]x, x \rangle +\langle (A+iB)x, y \rangle\langle y, (A+iB)x \rangle, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item If $\mathcal{A}$ is commutative, then \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \|-i\langle [A,B]x, x \rangle +\langle (A+iB)x, y \rangle\langle y, (A+iB)x \rangle\|, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \end{enumerate} \end{corollary} We also have following uncertainty principles. \begin{theorem}(\textbf{Noncommutative Maccone-Pati Uncertainty Principles}) Let $\mathcal{E}$ be a Hilbert C*-module over a unital C*-algebra $\mathcal{A}$. Let $A: \mathcal{D}(A)\to \mathcal{E}$ and $B: \mathcal{D}(B)\to \mathcal{E}$ be self-adjoint morphisms. Then for all $x \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\langle x, x \rangle =1$, we have \begin{enumerate}[\upshape(i)] \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \langle y, (A+B)x \rangle\langle (A+B)x, y \rangle-\|\langle \{A,B\}x, x \rangle -\{\langle Ax, x \rangle, \langle Bx, x \rangle\}\|, \\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\| \leq1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \langle y, (A-B)x \rangle\langle (A-B)x, y \rangle-\|\langle \{A,B\}x, x \rangle -\{\langle Ax, x \rangle, \langle Bx, x \rangle\}\|\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\| \leq1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \frac{\|\langle y, (A+B)x \rangle\langle (A+B)x, y \rangle+\langle (A-B)x, y \rangle\langle y, (A-B)x \rangle\|}{2},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\| \leq1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \langle y, (A+iB)x \rangle\langle (A+iB)x, y \rangle-\|\langle [A,B]x, x \rangle +[\langle Ax, x \rangle, \langle Bx, x \rangle]\|,\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\| \leq1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2&\geq \langle y, (A-iB)x \rangle\langle (A-iB)x, y \rangle-\|\langle [A,B]x, x \rangle +[\langle Ax, x \rangle, \langle Bx, x \rangle]\|,\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\| \leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \end{enumerate} \end{theorem} \begin{proof} Let $x \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\langle x, x \rangle =1$. Let $y \in \mathcal{E}$ be such that $ \|y\|\leq 1 $ and $ \langle x,y \rangle =0.$ \begin{enumerate}[\upshape(i)] \item \begin{align*} &\langle y, (A+B)x \rangle \langle (A+B)x, y \rangle\\ &=\langle y, Ax-\langle Ax, x \rangle x+(Bx-\langle Bx, x \rangle x) \rangle\langle Ax-\langle Ax, x \rangle x+(Bx-\langle Bx, x \rangle x), y\rangle\\ &\leq \|\langle (Ax-\langle Ax, x \rangle x)+ (Bx-\langle Bx, x \rangle x), (Ax-\langle Ax, x \rangle x)+ (Bx-\langle Bx, x \rangle x)\rangle\|\langle y, y \rangle\\ &\leq \|\langle (Ax-\langle Ax, x \rangle x)+ (Bx-\langle Bx, x \rangle x), (Ax-\langle Ax, x \rangle x)+ (Bx-\langle Bx, x \rangle x)\rangle\|\|\langle y, y \rangle\|\\ &\leq \|\langle Ax-\langle Ax, x \rangle x, Ax-\langle Ax, x \rangle x\rangle +\langle Bx-\langle Bx, x \rangle x, Bx-\langle Bx, x \rangle x\rangle \\ &\quad +\langle Bx-\langle Bx, x \rangle x, Ax-\langle Ax, x \rangle x\rangle+\langle Ax-\langle Ax, x \rangle x, Bx-\langle Bx, x \rangle x\rangle\|\\ &=\|d_x(A)^2+d_x(B)^2+(\langle Bx, Ax \rangle -\langle Bx, x \rangle\langle Ax, x \rangle)+\langle Ax, Bx \rangle -\langle Ax, x \rangle\langle Bx, x \rangle\|\\ &\leq \|d_x(A)^2+d_x(B)^2\|+\|\langle \{A,B\}x, x \rangle -\{\langle Ax, x \rangle, \langle Bx, x \rangle\}\|. \end{align*} Therefore \begin{align*} \Delta_x(A)^2+\Delta_x(B)^2\geq \|d_x(A)^2+d_x(B)^2\|\geq \langle y, (A+B)x \rangle\langle (A+B)x, y \rangle-\|\langle \{A,B\}x, x \rangle -\{\langle Ax, x \rangle, \langle Bx, x \rangle\}\|. \end{align*} \item Similar to (i). \item \begin{align*} &\langle y, (A+B)x \rangle \langle (A+B)x, y \rangle+\langle y, (A-B)x \rangle \langle (A-B)x, y \rangle=2\langle y, Ax \rangle \langle Ax, y \rangle +2\langle y, Bx \rangle \langle Bx, y \rangle\\ &=2\langle y, Ax-\langle Ax, x \rangle x\rangle \langle Ax-\langle Ax, x \rangle x, y \rangle +2\langle y, Bx-\langle Bx, x \rangle x \rangle \langle Bx-\langle Bx, x \rangle x, y \rangle\\ &\leq 2 \|\langle Ax-\langle Ax,x \rangle x, Ax-\langle Ax, x \rangle x \rangle \|\langle y, y \rangle+ 2\|\langle Bx-\langle Bx,x \rangle x, Bx-\langle Bx, x \rangle x \rangle\|\langle y, y \rangle\\ &\leq 2\Delta_x(A)^2+2\Delta_x(B)^2. \end{align*} \item \begin{align*} &\langle y, (A+iB)x \rangle\langle (A+iB)x, y \rangle= \langle y, Ax+iBx \rangle\langle Ax+iBx, y \rangle\\ &= \langle y, Ax-\langle Ax, x \rangle x+i(Bx-\langle Bx, x \rangle x) \rangle\langle Ax-\langle Ax, x \rangle x+i(Bx-\langle Bx, x \rangle x), y\rangle\\ &\leq \|\langle (Ax-\langle Ax, x \rangle x)+i (Bx-\langle Bx, x \rangle x), (Ax-\langle Ax, x \rangle x)+i (Bx-\langle Bx, x \rangle x)\rangle\| \langle y, y \rangle\\ &\leq \|\langle Ax-\langle Ax, x \rangle x, Ax-\langle Ax, x \rangle x\rangle +\langle Bx-\langle Bx, x \rangle x, Bx-\langle Bx, x \rangle x\rangle \\ &\quad +i\langle Bx-\langle Bx, x \rangle x, Ax-\langle Ax, x \rangle x\rangle-i\langle Ax-\langle Ax, x \rangle x, Bx-\langle Bx, x \rangle x\rangle\|\\ &=\|d_x(A)^2+d_x(B)^2+i(\langle Bx, Ax \rangle -\langle Bx, x \rangle\langle Ax, x \rangle)-i(\langle Ax, Bx \rangle -\langle Ax, x \rangle\langle Bx, x \rangle)\|\\ &=\|d_x(A)^2+d_x(B)^2\|+\|(\langle Bx, Ax \rangle -\langle Bx, x \rangle\langle Ax, x \rangle)-(\langle Ax, Bx \rangle -\langle Ax, x \rangle\langle Bx, x \rangle)\|\\ &=\|d_x(A)^2+d_x(B)^2\|+\|\langle [A,B]x, x \rangle +[\langle Ax, x \rangle, \langle Bx, x \rangle]\|. \end{align*} Therefore \begin{align*} &\Delta_x(A)^2+\Delta_x(B)^2\geq \|d_x(A)^2+d_x(B)^2\|\\ &\geq \langle y, (A+iB)x \rangle\langle (A+iB)x, y \rangle-\|\langle [A,B]x, x \rangle +[\langle Ax, x \rangle, \langle Bx, x \rangle]\|. \end{align*} \item Similar to (iv). \end{enumerate} \end{proof} \begin{theorem} Let $\mathcal{E}$ be a Hilbert C*-module over a unital commutative C*-algebra $\mathcal{A}$. Let $A:\mathcal{D}(A)\to \mathcal{E}$ and $B: \mathcal{D}(B)\to \mathcal{E}$ be self-adjoint morphisms. Then for all $x \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\langle x, x \rangle =1$, we have \begin{enumerate}[\upshape(i)] \item If $d_x(A)$, $d_x(B)$ are invertible, then \begin{align*} d_x(A)d_x(B)&\geq \frac{-i\langle [A,B]x, x \rangle}{2-\left\langle \left(\frac{A}{d_x(A)}+\frac{iB}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}+\frac{iB}{d_x(B)}\right)x\right \rangle},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)\Delta_x(B)&\geq \frac{-i\langle [A,B]x, x \rangle}{2-\left\langle \left(\frac{A}{\Delta_x(A)}+\frac{iB}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}+\frac{iB}{\Delta_x(B)}\right)x\right \rangle},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item If $d_x(A)$, $d_x(B)$ are invertible, then \begin{align*} d_x(A)d_x(B)&\geq \frac{i\langle [A,B]x, x \rangle}{2-\left\langle \left(\frac{A}{d_x(A)}-\frac{iB}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}-\frac{iB}{d_x(B)}\right)x\right \rangle},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)\Delta_x(B)&\geq \frac{i\langle [A,B]x, x \rangle}{2-\left\langle \left(\frac{A}{\Delta_x(A)}-\frac{iB}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}-\frac{iB}{\Delta_x(B)}\right)x\right \rangle},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item If $d_x(A)$, $d_x(B)$ are invertible, then \begin{align*} d_x(A)d_x(B)&\geq \frac{2\langle Ax, x \rangle\langle Bx, x \rangle -\langle \{A,B\}x, x \rangle}{2-\left\langle \left(\frac{A}{d_x(A)}+\frac{B}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}+\frac{B}{d_x(B)}\right)x\right \rangle},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)\Delta_x(B)&\geq \frac{2\langle Ax, x \rangle\langle Bx, x \rangle -\langle \{A,B\}x, x \rangle}{2-\left\langle \left(\frac{A}{\Delta_x(A)}+\frac{B}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}+\frac{B}{\Delta_x(B)}\right)x\right \rangle},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item If $d_x(A)$, $d_x(B)$ are invertible, then \begin{align*} d_x(A)d_x(B)&\geq \frac{-2\langle Ax, x \rangle\langle Bx, x \rangle +\langle \{A,B\}x, x \rangle}{2-\left\langle \left(\frac{A}{d_x(A)}-\frac{B}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}-\frac{B}{d_x(B)}\right)x\right \rangle},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \item \begin{align*} \Delta_x(A)\Delta_x(B)&\geq \frac{-2\langle Ax, x \rangle\langle Bx, x \rangle +\langle \{A,B\}x, x \rangle}{2-\left\langle \left(\frac{A}{\Delta_x(A)}-\frac{B}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}-\frac{B}{\Delta_x(B)}\right)x\right \rangle},\\ &\quad \forall y \in \mathcal{E} \text{ satisfying } \|y\|\leq 1 \text{ and } \langle x,y \rangle =0. \end{align*} \end{enumerate} \end{theorem} \begin{proof} Let $x \in \mathcal{D}(AB)\cap \mathcal{D}(BA)$ with $\langle x, x \rangle =1$. Let $y \in \mathcal{E}$ be such that $ \|y\|\leq 1 $ and $ \langle x,y \rangle =0.$ \begin{enumerate}[\upshape(i)] \item Since $\mathcal{A}$ is commutative and $d_x(A)$, $d_x(B)$ are invertible, \begin{align*} &\left\langle \left(\frac{A}{d_x(A)}+\frac{iB}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}+\frac{iB}{d_x(B)}\right)x\right \rangle\\ &=\left\langle \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}+\frac{i(Bx-\langle Bx, x \rangle x)}{d_x(B)}, y\right \rangle \left\langle y, \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}+\frac{i(Bx-\langle Bx, x \rangle x)}{d_x(B)}\right \rangle\\ &\leq \|\langle y, y \rangle \|\left\langle \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}+\frac{i(Bx-\langle Bx, x \rangle x)}{d_x(B)}, \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}+\frac{i(Bx-\langle Bx, x \rangle x)}{d_x(B)}\right \rangle\\ &\leq \left\langle \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}, \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}\right \rangle+\left\langle \frac{Bx-\langle Bx, x \rangle x}{d_x(B)}, \frac{Bx-\langle Bx, x \rangle x}{d_x(B)}\right \rangle\\ &\quad +i\left\langle \frac{Bx-\langle Bx, x \rangle x}{d_x(B)}, \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}\right \rangle-i\left\langle \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}, \frac{Bx-\langle Bx, x \rangle x}{d_x(B)}\right \rangle\\ &=1+1+\frac{i\langle Bx, Ax \rangle-i\langle Bx, x \rangle\langle Ax, x \rangle}{d_x(A)d_x(B)}+\frac{-i\langle Ax, Bx \rangle+i\langle Ax, x \rangle\langle Bx, x \rangle}{d_x(A)d_x(B)}\\ &=2+\frac{i\langle [A,B]x, x \rangle}{d_x(A)d_x(B)}. \end{align*} Therefore \begin{align*} &\frac{-i\langle [A,B]x, x \rangle}{d_x(A)d_x(B)}\leq 2-\left\langle \left(\frac{A}{d_x(A)}+\frac{iB}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}+\frac{iB}{d_x(B)}\right)x\right \rangle\\ &\implies \frac{-i\langle [A,B]x, x \rangle}{2-\left\langle \left(\frac{A}{d_x(A)}+\frac{iB}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}+\frac{iB}{d_x(B)}\right)x\right \rangle}\leq d_x(A)d_x(B). \end{align*} \item Since $\mathcal{A}$ is commutative, \begin{align*} &\left\langle \left(\frac{A}{\Delta_x(A)}+\frac{iB}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}+\frac{iB}{\Delta_x(B)}\right)x\right \rangle\\ &=\left\langle \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}+\frac{i(Bx-\langle Bx, x \rangle x)}{\Delta_x(B)}, y\right \rangle \left\langle y, \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}+\frac{i(Bx-\langle Bx, x \rangle x)}{\Delta_x(B)}\right \rangle\\ &\leq \|\langle y, y \rangle \|\left\langle \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}+\frac{i(Bx-\langle Bx, x \rangle x)}{\Delta_x(B)}, \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}+\frac{i(Bx-\langle Bx, x \rangle x)}{\Delta_x(B)}\right \rangle\\ &\leq \left\langle \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}, \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}\right \rangle+\left\langle \frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}, \frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}\right \rangle\\ &\quad +i\left\langle \frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}, \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}\right \rangle-i\left\langle \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}, \frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}\right \rangle\\ &=1+1+\frac{i\langle Bx, Ax \rangle-i\langle Bx, x \rangle\langle Ax, x \rangle}{\Delta_x(A)\Delta_x(B)}+\frac{-i\langle Ax, Bx \rangle+i\langle Ax, x \rangle\langle Bx, x \rangle}{\Delta_x(A)\Delta_x(B)}\\ &=2+\frac{i\langle [A,B]x, x \rangle}{\Delta_x(A)\Delta_x(B)}. \end{align*} Therefore \begin{align*} &\frac{-i\langle [A,B]x, x \rangle}{\Delta_x(A)\Delta_x(B)}\leq 2-\left\langle \left(\frac{A}{\Delta_x(A)}+\frac{iB}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}+\frac{iB}{\Delta_x(B)}\right)x\right \rangle\\ &\implies \frac{-i\langle [A,B]x, x \rangle}{2-\left\langle \left(\frac{A}{\Delta_x(A)}+\frac{iB}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}+\frac{iB}{\Delta_x(B)}\right)x\right \rangle}\leq \Delta_x(A)\Delta_x(B). \end{align*} \item Similar to (i). \item Similar to (ii). \item Since $\mathcal{A}$ is commutative and $d_x(A)$, $d_x(B)$ are invertible, \begin{align*} &\left\langle \left(\frac{A}{d_x(A)}+\frac{B}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}+\frac{B}{d_x(B)}\right)x\right \rangle\\ &=\left\langle \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}+\frac{Bx-\langle Bx, x \rangle x}{d_x(B)}, y\right \rangle \left\langle y, \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}+\frac{Bx-\langle Bx, x \rangle x}{d_x(B)}\right \rangle\\ &\leq \|\langle y, y \rangle \|\left\langle \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}+\frac{Bx-\langle Bx, x \rangle x}{d_x(B)}, \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}+\frac{Bx-\langle Bx, x \rangle x}{d_x(B)}\right \rangle\\ &\leq \left\langle \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}, \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}\right \rangle+\left\langle \frac{Bx-\langle Bx, x \rangle x}{d_x(B)}, \frac{Bx-\langle Bx, x \rangle x}{d_x(B)}\right \rangle\\ &\quad +\left\langle \frac{Bx-\langle Bx, x \rangle x}{d_x(B)}, \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}\right \rangle+\left\langle \frac{Ax-\langle Ax, x \rangle x}{d_x(A)}, \frac{Bx-\langle Bx, x \rangle x}{d_x(B)}\right \rangle\\ &=1+1+\frac{\langle Bx, Ax \rangle-\langle Bx, x \rangle\langle Ax, x \rangle}{d_x(A)d_x(B)}+\frac{\langle Ax, Bx \rangle-\langle Ax, x \rangle\langle Bx, x \rangle}{d_x(A)d_x(B)}\\ &=2+\frac{-2\langle Ax, x \rangle\langle Bx, x \rangle +\langle \{A,B\}x, x \rangle}{d_x(A)d_x(B)}. \end{align*} Therefore \begin{align*} &-\frac{-2\langle Ax, x \rangle\langle Bx, x \rangle +\langle \{A,B\}x, x \rangle}{d_x(A)d_x(B)}\leq 2-\left\langle \left(\frac{A}{d_x(A)}+\frac{B}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}+\frac{B}{d_x(B)}\right)x\right \rangle\\ &\implies \frac{2\langle Ax, x \rangle\langle Bx, x \rangle -\langle \{A,B\}x, x \rangle}{2-\left\langle \left(\frac{A}{d_x(A)}+\frac{B}{d_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{d_x(A)}+\frac{B}{d_x(B)}\right)x\right \rangle}\leq d_x(A)d_x(B). \end{align*} \item Since $\mathcal{A}$ is commutative, \begin{align*} &\left\langle \left(\frac{A}{\Delta_x(A)}+\frac{B}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}+\frac{B}{\Delta_x(B)}\right)x\right \rangle\\ &=\left\langle \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}+\frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}, y\right \rangle \left\langle y, \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}+\frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}\right \rangle\\ &\leq \|\langle y, y \rangle \|\left\langle \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}+\frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}, \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}+\frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}\right \rangle\\ &\leq \left\langle \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}, \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}\right \rangle+\left\langle \frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}, \frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}\right \rangle\\ &\quad +\left\langle \frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}, \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}\right \rangle+\left\langle \frac{Ax-\langle Ax, x \rangle x}{\Delta_x(A)}, \frac{Bx-\langle Bx, x \rangle x}{\Delta_x(B)}\right \rangle\\ &=1+1+\frac{\langle Bx, Ax \rangle-\langle Bx, x \rangle\langle Ax, x \rangle}{\Delta_x(A)\Delta_x(B)}+\frac{\langle Ax, Bx \rangle-\langle Ax, x \rangle\langle Bx, x \rangle}{\Delta_x(A)\Delta_x(B)}\\ &=2+\frac{2\langle Ax, x \rangle\langle Bx, x \rangle +\langle \{A,B\}x, x \rangle}{\Delta_x(A)\Delta_x(B)}. \end{align*} Therefore \begin{align*} &-\frac{-2\langle Ax, x \rangle\langle Bx, x \rangle +\langle \{A,B\}x, x \rangle}{\Delta_x(A)\Delta_x(B)}\leq 2-\left\langle \left(\frac{A}{\Delta_x(A)}+\frac{B}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}+\frac{B}{\Delta_x(B)}\right)x\right \rangle\\ &\implies \frac{2\langle Ax, x \rangle\langle Bx, x \rangle -\langle \{A,B\}x, x \rangle}{2-\left\langle \left(\frac{A}{\Delta_x(A)}+\frac{B}{\Delta_x(B)}\right)x, y\right \rangle \left\langle y, \left(\frac{A}{\Delta_x(A)}+\frac{B}{\Delta_x(B)}\right)x\right \rangle}\leq \Delta_x(A)\Delta_x(B). \end{align*} \item Similar to (v). \item Similar to (vi). \end{enumerate} \end{proof} \section{Acknowledgments} The author thanks anonymous reviewer for his/her constructive feedback, which significantly improved the final manuscript. \bibliographystyle{plain} \begin{thebibliography}{10} \bibitem{ARAMBASICBAKICMOSLEHIAN} Ljiljana Arambasic, Damir Bakic, and Mohammad~Sal Moslehian. \newblock A treatment of the {Cauchy}-{Schwarz} inequality in {$C^*$}-modules. \newblock {\em J. Math. Anal. Appl.}, 381(2):546--556, 2011. \bibitem{BELLOMONTE} G.~Bellomonte, S.~Ivkovic, and C.~Trapani. \newblock Banach bimodule-valued positive maps: inequalities and representations. \newblock {\em Banach J. Math. Anal.}, 20(12), 2026. \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{FUJIIFUJIIMOSLEHIANSEO} J.~I. Fujii, M.~Fujii, M.~S. Moslehian, and Y.~Seo. \newblock Cauchy-{S}chwarz inequality in semi-inner product {$C^*$}-modules via polar decomposition. \newblock {\em J. Math. Anal. Appl.}, 394(2):835--840, 2012. \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{ILLSEVICVAROSANEC} Dijana Ilisevic and Sanja Varosanec. \newblock On the {Cauchy}-{Schwarz} inequality and its reverse in semi-inner product {$C^*$}-modules. \newblock {\em Banach J. Math. Anal.}, 1(1):78--84, 2007. \bibitem{KAPLANSKY} Irving Kaplansky. \newblock Modules over operator algebras. \newblock {\em Amer. J. Math.}, 75:839--858, 1953. \bibitem{LANCE} E.~Christopher Lance. \newblock {\em Hilbert {$C^*$}-modules. {A} toolkit for operator algebraists}, volume 210 of {\em Lond. Math. Soc. Lect. Note Ser.} \newblock Cambridge: Univ. Press, 1995. \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{MANUILOVTROITSKY} V.~M. Manuilov and E.~V. Troitsky. \newblock {\em Hilbert {$C^*$}-modules}, volume 226 of {\em Transl. Math. Monogr.} \newblock Providence, RI: American Mathematical Society, 2005. \bibitem{PASCHKE} William~L. Paschke. \newblock Inner product modules over {$B^{\ast} $}-algebras. \newblock {\em Trans. Amer. Math. Soc.}, 182:443--468, 1973. \bibitem{RIEFFEL} Marc~A. Rieffel. \newblock Induced representations of {$C^{\ast} $}-algebras. \newblock {\em Advances in Math.}, 13:176--257, 1974. \bibitem{ROBERTSON} H.~P. Robertson. \newblock The uncertainty principle. \newblock {\em Phys. Rev.}, 34(1):163--164, 1929. \bibitem{SCHRODINGER} E.~Schr\"{o}dinger. \newblock About {H}eisenberg uncertainty relation. \newblock {\em Bulgar. J. Phys.}, 26(5-6):193--203 (2000), 1999. \bibitem{THOMSEN} Klaus Thomsen. \newblock {\em Hilbert {$C^*$}-modules, {$KK$}-theory and {$C^*$}-extensions}, volume~38 of {\em Var. Publ. Ser., Aarhus Univ.} \newblock Aarhus: Aarhus Universitet, Matematisk Institut, 1988. \bibitem{VONNEUMANNBOOK} John von Neumann. \newblock {\em Mathematical foundations of quantum mechanics}. \newblock Princeton University Press, Princeton, NJ, 2018. \bibitem{WEGGEOLSEN} Niels~Erik Wegge-Olsen. \newblock {\em K-theory and {$C^*$}-algebras: a friendly approach}. \newblock Oxford: Oxford University Press, 1993. \end{thebibliography} \end{document}