55 research outputs found
Macdonald operators and homological invariants of the colored Hopf link
Using a power sum (boson) realization for the Macdonald operators, we
investigate the Gukov, Iqbal, Kozcaz and Vafa (GIKV) proposal for the
homological invariants of the colored Hopf link, which include
Khovanov-Rozansky homology as a special case. We prove the polynomiality of the
invariants obtained by GIKV's proposal for arbitrary representations. We derive
a closed formula of the invariants of the colored Hopf link for antisymmetric
representations. We argue that a little amendment of GIKV's proposal is
required to make all the coefficients of the polynomial non-negative integers.Comment: 31 pages. Published version with an additional appendi
The MacMahon R-matrix
We introduce an -matrix acting on the tensor product of MacMahon
representations of Ding-Iohara-Miki (DIM) algebra
. This -matrix acts on pairs
of Young diagrams and retains the nice symmetry of the DIM algebra under
the permutation of three deformation parameters , and
. We construct the intertwining operator for a tensor product of
the horizontal Fock representation and the vertical MacMahon representation and
show that the intertwiners are permuted using the MacMahon -matrix.Comment: 39 page
Shiraishi functor and non-Kerov deformation of Macdonald polynomials
We suggest a further generalization of the hypergeometric-like series due to
M. Noumi and J. Shiraishi by substituting the Pochhammer symbol with a nearly
arbitrary function. Moreover, this generalization is valid for the entire
Shiraishi series, not only for its Noumi-Shiraishi part. The theta function
needed in the recently suggested description of the double-elliptic systems, 6d
N=2* SYM instanton calculus and the doubly-compactified network models, is a
very particular member of this huge family. The series depends on two kinds of
variables, and , and on a set of parameters, which becomes
infinitely large now. Still, one of the parameters, is distinguished by its
role in the series grading. When are restricted to a discrete subset
labeled by Young diagrams, the series multiplied by a monomial factor reduces
to a polynomial at any given order in . All this makes the map from
functions to the hypergeometric-like series very promising, and we call it
Shiraishi functor despite it remains to be seen, what are exactly the morphisms
that it preserves. Generalized Noumi-Shiraishi (GNS) symmetric polynomials
inspired by the Shiraishi functor in the leading order in can be obtained
by a triangular transform from the Schur polynomials and possess an interesting
grading. They provide a family of deformations of Macdonald polynomials, as
rich as the family of Kerov functions, still very different from them, and, in
fact, much closer to the Macdonald polynomials. In particular, unlike the Kerov
case, these polynomials do not depend on the ordering of Young diagrams in the
triangular expansion.Comment: 17 page
Selberg Integral and SU(N) AGT Conjecture
An intriguing coincidence between the partition function of super Yang-Mills
theory and correlation functions of 2d Toda system has been heavily studied
recently. While the partition function of gauge theory was explored by
Nekrasov, the correlation functions of Toda equation have not been completely
understood. In this paper, we study the latter in the form of Dotsenko-Fateev
integral and reduce it in the form of Selberg integral of several Jack
polynomials. We conjecture a formula for such Selberg average which satisfies
some consistency conditions and show that it reproduces the SU(N) version of
AGT conjecture.Comment: 35 pages, 5 figures; v2: minor modifications; v3: typos corrected,
references adde
A & B model approaches to surface operators and Toda theories
It has recently been argued by Alday et al that the inclusion of surface
operators in 4d N=2 SU(2) quiver gauge theories should correspond to insertions
of certain degenerate operators in the dual Liouville theory. So far only the
insertion of a single surface operator has been treated (in a semi-classical
limit). In this paper we study and generalise this proposal. Our approach
relies on the use of topological string theory techniques. On the B-model side
we show that the effects of multiple surface operator insertions in 4d N=2
gauge theories can be calculated using the B-model topological recursion
method, valid beyond the semi-classical limit. On the mirror A-model side we
find by explicit computations that the 5d lift of the SU(N) gauge theory
partition function in the presence of (one or many) surface operators is equal
to an A-model topological string partition function with the insertion of (one
or many) toric branes. This is in agreement with an earlier proposal by Gukov.
Our A-model results were motivated by and agree with what one obtains by
combining the AGT conjecture with the dual interpretation in terms of
degenerate operators. The topological string theory approach also opens up new
possibilities in the study of 2d Toda field theories.Comment: 43 pages. v2: Added references, including a reference to unpublished
work by S.Gukov; minor changes and clarifications
Instanton counting, Macdonald function and the moduli space of D-branes
We argue the connection of Nekrasov's partition function in the \Omega
background and the moduli space of D-branes, suggested by the idea of geometric
engineering and Gopakumar-Vafa invariants. In the instanton expansion of N=2
SU(2) Yang-Mills theory the Nakrasov's partition function with equivariant
parameters \epsilon_1, \epsilon_2 of toric action on C^2 factorizes correctly
as the character of SU(2)_L \times SU(2)_R spin representation. We show that up
to two instantons the spin contents are consistent with the Lefschetz action on
the moduli space of D2-branes on (local) F_0. We also present an attempt at
constructing a refined topological vertex in terms of the Macdonald function.
The refined topological vertex with two parameters of T^2 action allows us to
obtain the generating functions of equivariant \chi_y and elliptic genera of
the Hilbert scheme of n points on C^2 by the method of topological vertex.Comment: 33 pages, 2 figures, (v2) minor changes, references added, (v3)
Comments and more references adde
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