Jack function

Abstract: Introduction to $q$-analogues and symmetric functions Macdonald polynomials and the space of diagonal harmonics The $q, t$-Catalan numbers The $q, t$-Schroder polynomial Parking functions and the Hilbert series The shuffle conjecture The proof of the $q, t$-Schroder theorem The combinatorics and Macdonald polynomials The Loehr-Warrington conjecture Solutions to exercises Bibliography.

Abstract: In this paper, we introduce a new family of symmetric polynomials which depends on a parameter r. They are defined by specifying certain of their zeros. For the parameter values 1/2, 1, and 2 they have an interpretation in terms of Capelli identities. First, we give explicit formulas in some special cases. Then we show that the polynomials can also be defined in terms of difference equations. As a corollary we obtain that their top homogeneous part is a Jack polynomial. This is used to give a new proof of the Pieri formula for Jack polynomials.

Abstract: We derive a product rule satisfied by restricted Schur polynomials. We focus mostly on the case that the restricted Schur polynomial is built using two matrices, although our analysis easily extends to more than two matrices. This product rule allows us to compute exact multi-point correlation functions of restricted Schur polynomials, in the free field theory limit. As an example of the use of our formulas, we compute two point functions of certain single trace operators built using two matrices and three point functions of certain restricted Schur polynomials, exactly, in the free field theory limit. Our results suggest that gravitons become strongly coupled at sufficiently high energy, while the restricted Schur polynomials for totally antisymmetric representations remain weakly interacting at these energies. This is in perfect accord with the half-BPS (single matrix) results of hep-th/0512312. Finally, by studying the interaction of two restricted Schur polynomials we suggest a physical interpretation for the labels of the restricted Schur polynomial: the composite operator χR,(rn,rm)(Z,X) is constructed from the half BPS ``partons'' χrn(Z) and χrm(X).