Index of notation

$$\newcommand{\bigudot}{ \mathchoice{\mathop{\bigcup\mkern-15mu\cdot\mkern8mu}}{\mathop{\bigcup\mkern-13mu\cdot\mkern5mu}}{\mathop{\bigcup\mkern-13mu\cdot\mkern5mu}}{\mathop{\bigcup\mkern-13mu\cdot\mkern5mu}} }$$ $$\newcommand{\udot}{\cup\mkern-12.5mu\cdot\mkern6.25mu\!}$$ $$\require{AMScd}\newcommand{\d}[1][]{\mathrm{d}^{#1} }$$ Ordered symbols are notations which are (likely) to appear as they are given here, for example $$C([a,b],\mathbb{R})$$ denotes the continuous function on the interval $[a,b]$ that map to $\mathbb{R}$ - this is unlikely to be given any other way because "C" is for continuous.

Ordered symbols

These are ordered by symbols, and then by LaTeX names secondly, for example

$$A$$ comes before $$\mathbb{A}$$ comes before $$\mathcal{A}$$

Expression	Context	Details
$$\|\cdot\|$$	Functional Analysis Real Analysis	Denotes the Norm of a vector
$$\|f\|_{C^k}$$	Functional Analysis	This Norm is defined by $$\|f\|_{C^k}=\sum^k_{i=0}\sup_{t\in[0,1]}(|f^{(i)}(t)|)$$ - note $$f^{(i)}$$ is the $$i^\text{th}$$ derivative.
$$\|f\|_{L^p}$$	Functional Analysis	$$\|f\|_{L^p}=\left(\int^1_0|f(t)|^pdt\right)^\frac{1}{p}$$ - it is a Norm on $$\mathcal{C}([0,1],\mathbb{R})$$
$$\|f\|_\infty$$	Functional Analysis Real Analysis	It is a norm on $$C([a,b],\mathbb{R})$$ , given by $$\|f\|_\infty=\sup_{x\in[a,b]}(|f(x)|)$$
$$C^\infty$$	Differential Geometry Manifolds	That a function has continuous (partial) derivatives of all orders, it is a generalisation of $$C^k$$ functions
$$C^k$$ [at $p$]	Differential Geometry Manifolds	A function is said to be $$C^k$$ [at $p$] if all (partial) derivatives of all orders exist and are continuous [at $p$]
$$C^\infty_p$$	Differential Geometry Manifolds	$$C^\infty_p(A)$$ denotes the set of all germs of $$C^\infty$$ functions on $A$ at $p$ The set of all germs of smooth functions at a point
$$C^k([a,b],\mathbb{R})$$	Functional Analysis Real Analysis	It is the set of all functions $$:[a,b]\rightarrow\mathbb{R}$$ that are continuous and have continuous derivatives up to (and including) order $$k$$ The unit interval will be assumed when missing
$$D_a(A)$$ Common: $$D_a(\mathbb{R}^n)$$	Differential Geometry Manifolds	Denotes Set of all derivations at a point - Not to be confused with Set of all derivations of a germ which is denoted $\mathcal{D}_p(A)$ Note: This is my/Alec's notation for it, as the author uses $T_p(A)$ - which looks like Tangent space - the letter T is too misleading to allow this, and a lot of other books use T for Tangent space
$$\mathcal{D}_a(A)$$ Common: $$\mathcal{D}_a(\mathbb{R}^n)$$	Differential Geometry Manifolds	Denotes Set of all derivations of a germ - Not to be confused with Set of all derivations at a point which is sometimes denoted $T_p(A)$
$$\bigudot_i A_i$$	Measure Theory	Makes it explicit that the items in the union (the $$A_i$$ ) are pairwise disjoint, that is for any two their intersection is empty
$$\ell^p(\mathbb{F})$$	Functional Analysis	The set of all bounded sequences, that is $$\ell^p(\mathbb{F})=\{(x_1,x_2,...)|x_i\in\mathbb{F},\ \sum^\infty_{i=1}|x_i|^p<\infty\}$$
$$\mathcal{L}^p$$	Measure Theory	$$\mathcal{L}^p(\mu)=\{u:X\rightarrow\mathbb{R}|u\in\mathcal{M},\ \int|u|^pd\mu<\infty\},\ p\in[1,\infty)\subset\mathbb{R}$$ $$(X,\mathcal{A},\mu)$$ is a measure space. The class of all measurable functions for which $$|f|^p$$ is integrable
$$L^p$$	Measure Theory	Same as $$\mathcal{L}^p$$
$$T_p(A)$$ Common: $$T_p(\mathbb{R}^n)$$	Differential Geometry Manifolds	The tangent space at a point $a$ Sometimes denoted $\mathbb{R}^n_a$ - Note: sometimes can mean Set of all derivations at a point which is denoted $D_a(\mathbb{R}^n)$ and not to be confused with $$\mathcal{D}_a(\mathbb{R}^n)$$ which denotes Set of all derivations of germs

Unordered symbols

Expression	Context	Details
$$\mathcal{A}/\mathcal{B}$$ -measurable	Measure Theory	There exists a Measurable map between the $\sigma$-algebras
$a\cdot b$	Anything with vectors	Vector dot product