N  of natural numbers {\displaystyle \mathbb {N} {\mbox{ of natural numbers}}} D  is the open disc domain {\displaystyle \mathbb {D} {\mbox{ is the open disc domain}}} b  is the open domain nature boundary {\displaystyle \mathbb {b} {\mbox{ is the open domain nature boundary}}} C ±  is the complex half-plane {\displaystyle \mathbb {C} ^{\pm }{\mbox{ is the complex half-plane}}} m e g a  is a root of unity {\displaystyle mega{\mbox{ is a root of unity}}} ∇  is the gradient {\displaystyle \nabla {\mbox{ is the gradient}}} Δ = ∇ ⋅ ∇  is the Laplace operator {\displaystyle \Delta =\nabla \cdot \nabla {\mbox{ is the Laplace operator}}} Λ  is Dirichlet-to-Neumann operator {\displaystyle \Lambda {\mbox{ is Dirichlet-to-Neumann operator}}} D x  is a diagonal matrix w/the vector  x  on the diagonal  ( D x 1 = x ) {\displaystyle D_{x}{\mbox{ is a diagonal matrix w/the vector }}x{\mbox{ on the diagonal }}(D_{x}1=x)} D A  is the diagonal matrix, coinciding on diagonal w/the matrix  A {\displaystyle D_{A}{\mbox{ is the diagonal matrix, coinciding on diagonal w/the matrix }}A} y , λ  is eigenvalue of operator/matrix {\displaystyle y,\lambda {\mbox{ is eigenvalue of operator/matrix}}} m a ( A )  is spectrum of matrix  A ,  zeros of characteristic polynomial  {\displaystyle ma(A){\mbox{ is spectrum of matrix }}A,{\mbox{ zeros of characteristic polynomial }}} ρ ( A )  is the characteristic polynomial of matrix  A {\displaystyle \rho (A){\mbox{ is the characteristic polynomial of matrix }}A} τ  is the Cayley transform {\displaystyle \tau {\mbox{ is the Cayley transform}}} e g a  is a continuous domain {\displaystyle ega{\mbox{ is a continuous domain}}} G / G ∗  is graph or network and its dual {\displaystyle G/G^{*}{\mbox{ is graph or network and its dual}}} V G  is the set of vertices of a graph {\displaystyle V_{G}{\mbox{ is the set of vertices of a graph}}} E G  is the set of edges of a graph {\displaystyle E_{G}{\mbox{ is the set of edges of a graph}}} M G  is the medial graph of an embedded graph  G {\displaystyle M_{G}{\mbox{ is the medial graph of an embedded graph }}G} c  is conductivity {\displaystyle c{\mbox{ is conductivity}}}
{'wiki_source': 'wikibooks', 'other_info': "{'content_model': 'wikitext', 'language': 'en', 'title': 'On 2D Inverse Problems/Notation', 'type': 'text'}"}