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authorPrefetch2021-02-21 20:53:46 +0100
committerPrefetch2021-02-21 20:53:46 +0100
commit15bfb7730801809704c6561e20c5ca47627b2d79 (patch)
tree0f911134a4b040cb43b1acbecfb43931bd5c0837 /latex/know/concept/hilbert-space
parentd33ac5f01a6599406d516edfd45b9938795cea6d (diff)
Add "Gram-Schmidt method"
Diffstat (limited to 'latex/know/concept/hilbert-space')
-rw-r--r--latex/know/concept/hilbert-space/source.md13
1 files changed, 6 insertions, 7 deletions
diff --git a/latex/know/concept/hilbert-space/source.md b/latex/know/concept/hilbert-space/source.md
index 7d2ea05..3f6ceb5 100644
--- a/latex/know/concept/hilbert-space/source.md
+++ b/latex/know/concept/hilbert-space/source.md
@@ -41,12 +41,11 @@ other. Otherwise, they would be **linearly dependent**.
A vector space $\mathbb{V}$ has **dimension** $N$ if only up to $N$ of
its vectors can be linearly indepedent. All other vectors in
-$\mathbb{V}$ can then be written as a **linear combination** of these $N$
-so-called **basis vectors**.
+$\mathbb{V}$ can then be written as a **linear combination** of these $N$ **basis vectors**.
Let $\vu{e}_1, ..., \vu{e}_N$ be the basis vectors, then any
vector $V$ in the same space can be **expanded** in the basis according to
-the unique "weights" $v_n$, known as the **components** of the vector $V$
+the unique weights $v_n$, known as the **components** of $V$
in that basis:
$$\begin{aligned}
@@ -89,9 +88,9 @@ Two vectors $U$ and $V$ are **orthogonal** if their inner product
$\braket{U}{V} = 0$. If in addition to being orthogonal, $|U| = 1$ and
$|V| = 1$, then $U$ and $V$ are known as **orthonormal** vectors.
-Orthonormality is a desirable property for basis vectors, so if they are
+Orthonormality is desirable for basis vectors, so if they are
not already orthonormal, it is common to manually derive a new
-orthonormal basis from them using e.g. the Gram-Schmidt method.
+orthonormal basis from them using e.g. the [Gram-Schmidt method](/know/concept/gram-schmidt-method).
As for the implementation of the inner product, it is given by:
@@ -157,7 +156,7 @@ The concept of orthonormality must be also weakened. A finite function
$f(x)$ can be normalized as usual, but the basis vectors $x$ themselves
cannot, since each represents an infinitesimal section of the real line.
-The rationale in this case is that the identity operator $\hat{I}$ must
+The rationale in this case is that action of the identity operator $\hat{I}$ must
be preserved, which is given here in [Dirac notation](/know/concept/dirac-notation/):
$$\begin{aligned}
@@ -172,7 +171,7 @@ $$\begin{aligned}
= \int_a^b \braket{x}{\xi} f(\xi) \dd{\xi}
\end{aligned}$$
-For the latter integral to turn into $f(x)$, it is clear that
+For the latter integral to turn into $f(x)$, it is plain to see that
$\braket{x}{\xi}$ must be a [Dirac delta function](/know/concept/dirac-delta-function/),
i.e $\braket{x}{\xi} = \delta(x - \xi)$: