claim: Petyr Baelish is nicknamed Littlefinger by George R.R. Martin.
evidence: In mathematics , Atkin -- Lehner theory is part of the theory of modular forms , in which the concept of newform is defined in such a way that the theory of Hecke operators can be extended to higher level .. A newform is a cusp form ` new ' at a given level N , where the levels are the nested congruence subgroups  :. cusp form. cusp form. of the modular group , with N ordered by divisibility .. modular group. modular group. divisibility. divisibility. That is , if M divides N , Γ0 -LRB- N -RRB- is a subgroup of Γ0 -LRB- M -RRB- .. subgroup. subgroup. The oldforms for Γ0 -LRB- N -RRB- are those modular forms f of level N of the form g -LRB- d τ -RRB- for modular forms g of level M with M a proper divisor of N , where d divides N / M .. The newforms are defined as a vector subspace of the modular forms of level N , complementary to the space spanned by the oldforms , i.e. the orthogonal space with respect to the Petersson inner product .. Petersson inner product. Petersson inner product. The Hecke operators , which act on the space of all cusp forms , preserve the subspace of newforms and are self-adjoint and commuting operators -LRB- with respect to the Petersson inner product -RRB- when restricted to this subspace .. Petersson inner product. Petersson inner product. self-adjoint. self-adjoint operator. Therefore , the algebra of operators on newforms they generate is a finite-dimensional C * - algebra that is commutative ; and by the spectral theory of such operators , there exists a basis for the space of newforms consisting of eigenforms for the full Hecke algebra .. spectral theory. spectral theorem. Hecke algebra. Hecke algebra