1 Algebraic and Analytic MethodsNotation

§1.1 Special Notation

(For other notation see Notation for the Special Functions.)

x,y real variables.
z complex variable in §§1.2(i), 1.9–1.11, real variable in §§1.5–1.6.
w complex variable in §§1.9–1.11.
j,k,ℓ integers.
m,n nonnegative integers, unless specified otherwise.
⟨f,g⟩ inner, or scalar, product for real or complex vectors or functions.
L2⁡(X,dα) the space of all Lebesgue–Stieltjes measurable functions on X which are square integrable with respect to dα.
ϕ a testing function.
⟨Λ,ϕ⟩ action of distribution Λ on test function ϕ.
deg degree.
primes derivatives with respect to the variable, except where indicated otherwise.
𝐮, 𝐯 column vectors.
𝐄n the space of all n-dimensional vectors.
𝐀 or [ai,j] or [ai⁢j] matrix with elements ai,j or ai⁢j.
𝐀−1 inverse of the square matrix 𝐀
𝐈 identity matrix
det(𝐀) determinant of the square matrix 𝐀
tr⁡(𝐀) trace of the square matrix 𝐀
etr⁡(𝐀) exponential of tr⁡(𝐀)
𝐀∗ adjoint of the square matrix 𝐀
𝐀¯ complex conjugate of the matrix 𝐀
𝐀T transpose of the matrix 𝐀
𝐀H Hermitian conjugate of the matrix 𝐀
ℒ linear operator defined on a manifold ℳ
ℒ∗ adjoint of ℒ defined on the dual manifold ℳ∗

In the physics, applied maths, and engineering literature a common alternative to a¯ is a∗, a being a complex number or a matrix; the Hermitian conjugate of 𝐀 is usually being denoted 𝐀†.