Notation overview

Since manifolds include a reasonable amount of elements and functions, the following list tries to keep an overview of used notation throughout Manifolds.jl. The order is alphabetical by name. They might be used in a plain form within the code or when referring to that code. This is for example the case with the calligraphic symbols.

Within the documented functions, the utf8 symbols are used whenever possible, as long as that renders correctly in TeX\TeX within this documentation.

SymbolDescriptionAlso usedComment
τp\tau_paction map by group element ppLp\mathrm{L}_p, Rp\mathrm{R}_peither left or right
×\timesCartesian product of two manifoldssee ProductManifold
^{\wedge}(n-ary) Cartesian power of a manifoldsee PowerManifold
TpMT^*_p \mathcal Mthe cotangent space at pp
ξ\xia cotangent vector from TpMT^*_p \mathcal Mξ1,ξ2,,η,ζ\xi_1, \xi_2,\ldots,\eta,\zetasometimes written with base point ξp\xi_p.
dϕp(q)\mathrm{d}\phi_p(q)Differential of a map ϕ:MN\phi: \mathcal M \to \mathcal N with respect to pp at a point qq. For functions of multiple variables, for example ϕ(p,p1)\phi(p, p_1) where pMp \in \mathcal M and p1M1p_1 \in \mathcal M_1, variable pp is explicitly stated to specify with respect to which argument the differential is calculated.dϕq\mathrm{d}\phi_q, (dϕ)q(\mathrm{d}\phi)_q, (ϕ)q(\phi_*)_q, Dpϕ(q)D_p\phi(q)pushes tangent vectors XTqMX \in T_q \mathcal M forward to dϕp(q)[X]Tϕ(q)N\mathrm{d}\phi_p(q)[X] \in T_{\phi(q)} \mathcal N
nndimension (of a manifold)n1,n2,,m,dim(M)n_1,n_2,\ldots,m, \dim(\mathcal M)for the real dimension sometimes also dimR(M)\dim_{\mathbb R}(\mathcal M)
d(,)d(\cdot,\cdot)(Riemannian) distancedM(,)d_{\mathcal M}(\cdot,\cdot)
exppX\exp_p Xexponential map at pMp \in \mathcal M of a vector XTpMX \in T_p \mathcal Mexpp(X)\exp_p(X)
FFa fibersee VectorBundleFibers
F\mathbb Fa field, usually F{R,C,H}\mathbb F \in \{\mathbb R,\mathbb C, \mathbb H\}, i.e. the real, complex, and quaternion numbers, respectively.field a manifold or a basis is based on
γ\gammaa geodesicγp;q\gamma_{p;q}, γp,X\gamma_{p,X}connecting two points p,qp,q or starting in pp with velocity XX.
f(p)\nabla f(p)gradient of function f ⁣:MRf \colon \mathcal{M} \to \mathbb{R} at pMp \in \mathcal{M}
\circa group operation
H\cdot^\mathrm{H}Hermitian or conjugate transposed
eeidentity element of a group
IkI_kidentity matrix of size k×kk\times k
kkindicesi,ji,j
,\langle\cdot,\cdot\rangleinner product (in TpMT_p \mathcal M),p,gp(,)\langle\cdot,\cdot\rangle_p, g_p(\cdot,\cdot)
g\mathfrak ga Lie algebra
G\mathcal{G}a (Lie) group
logpq\log_p qlogarithmic map at pMp \in \mathcal M of a point qMq \in \mathcal Mlogp(q)\log_p(q)
M\mathcal Ma manifoldM1,M2,,N\mathcal M_1, \mathcal M_2,\ldots,\mathcal N
Exp\operatorname{Exp}the matrix exponential
Log\operatorname{Log}the matrix logarithm
PqpX\mathcal P_{q\gets p}Xparallel transportof the vector XX from TpMT_p\mathcal M to TqMT_q\mathcal M
ppa point on M\mathcal Mp1,p2,,qp_1, p_2, \ldots,qfor 3 points one might use x,y,zx,y,z
Ξ\Xia set of tangent vectors{X1,,Xn}\{X_1,\ldots,X_n\}
TpMT_p \mathcal Mthe tangent space at pp
XXa tangent vector from TpMT_p \mathcal MX1,X2,,Y,ZX_1,X_2,\ldots,Y,Zsometimes written with base point XpX_p
tr\operatorname{tr}trace (of a matrix)
T\cdot^\mathrm{T}transposed
BBa vector bundle
0k0_kthe k×kk\times k zero matrix.