This page lists the notation we use across the Bempp website, and may be a useful reference.
Domains, surfaces, etc.
Symbol(s) |
Meaning |
 |
A domain |
 |
An interior domain |
 |
An exterior domain |
 |
The boundary of a domain |
 |
The outward point normal to the surface  |
Points, vectors, etc.
Symbol(s) |
Meaning |
Bold lowercase: , , … |
A point in 3D space |
, and  |
The three components of a point  |
Operators and matrices
Symbol(s) |
Meaning |
Curly capitals: , , … |
Potential operators |
Sans-serif capitals: , , … |
Boundary operators |
Serif capitals with subscripts: , , … |
Matrices arising from discretisation of an operator |
Serif capitals: , , … |
Other matrices |
,  |
Interior and exterior Calderón projectors |
 |
Multitrace operator |
,  |
Identity operators |
, ,  |
Single layer operators/matrices |
, ,  |
Double layer operators/matrices |
,  |
Adjoint double layer operators/matrices |
,  |
Hypersingular operators/matrices |
, ,  |
Electric field operators/matrices |
, ,  |
Magnetic field operators/matrices |
Functions and spaces
Symbol(s) |
Meaning |
 |
The domain of an operator |
 |
The range of an operator |
 |
The dual to the range of an operator |
Lowercase Greek letters: , , … Lowercase Roman letters: , , … |
Scalar valued functions |
Capital Greek letters: , , … Bold capital Roman letters: , , … |
Vector valued functions |
Functions with subscripts: , , , … |
Basis functions of a discrete space |