From: hackbard Date: Sun, 19 Feb 2012 17:28:00 +0000 (+0100) Subject: hopefully finished respective math stuff, finally! X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bc36ee251b928962cf2431d6582e5a5dd9cca682;p=lectures%2Flatex.git hopefully finished respective math stuff, finally! --- diff --git a/physics_compact/math_app.tex b/physics_compact/math_app.tex index f8361e8..f1ac777 100644 --- a/physics_compact/math_app.tex +++ b/physics_compact/math_app.tex @@ -139,7 +139,7 @@ and the usual rules of matrix multiplication. \end{remark} \begin{definition}[Outer product] -If $\vec{u}\in U$, $\vec{v},\vec{w}\in V$ are vectors within the respective vector spaces and $\varphi_{\vec{v}}\in V^{\dagger}$ is a linear functional of the dual space $V^{\dagger}$ of $V$ determined in some way from $\vec{v}$ (e.g.\ as in \eqref{eq:ip_mapping}), +If $\vec{u}\in U$, $\vec{v},\vec{w}\in V$ are vectors within the respective vector spaces and $\varphi_{\vec{v}}\in V^{\dagger}$ is a linear functional of the dual space $V^{\dagger}$ of $V$ (determined in some way by $\vec{v}$), the outer product $\vec{u}\otimes\vec{v}$ is defined as the tensor product of $\varphi_{\vec{v}}$ and $\vec{u}$, which constitutes a map $A:V\rightarrow U$ by \begin{equation} @@ -150,9 +150,10 @@ where $\varphi_{\vec{v}}(\vec{w})$ denotes the linear functional $\varphi_{\vec{ \end{definition} \begin{remark} -In matrix formalism, with respect to a given basis ${\vec{e}_i}$ of $\vec{u}$ and ${\vec{e}'_i}$ of $\vec{v}$, + +In matrix formalism, if $\varphi_{\vec{v}}$ is defined as in \eqref{eq:ip_mapping} and if $\vec{u}=\sum_i^m \vec{e}_iu_i$ and $\vec{v}=\sum_i^n\vec{e}'_iv_i$, -the outer product can be written as matrix $A$ as +the standard form of the outer product can be written as the matrix \begin{equation} \vec{u}\otimes\vec{v}=A=\left( \begin{array}{c c c c} @@ -162,19 +163,19 @@ u_2v_1^* & u_2v_2^* & \cdots & u_2v_n^*\\ u_mv_1^* & u_mv_2^* & \cdots & u_mv_n^*\\ \end{array} \right) -\text{ .} +\text{ ,} \end{equation} - -The matrix can be equivalently obtained by matrix multiplication: +which can be equivalently obtained by the rulrs of matrix multiplication \begin{equation} \vec{u}\otimes\vec{v}=\vec{u}\vec{v}^{\dagger} \text{ ,} \end{equation} if $\vec{u}$ and $\vec{v}$ are represented as $m\times 1$ and $n\times 1$ column vectors, respectively. -Here, $\vec{v}^{\dagger}$ represents the conjugate transpose of $\vec{v}$. -By definition, and as can be easily seen in the matrix representation, the following identity holds: +Here, again, $\vec{v}^{\dagger}$ represents the conjugate transpose of $\vec{v}$. +By definition, and as can be easily seen in matrix representation, the identity \begin{equation} (\vec{u}\otimes\vec{v})\vec{w}=\vec{u}(\vec{v},\vec{w}) \end{equation} +holds. \end{remark} \section{Spherical coordinates}