57 citations · 98 across the 6 of their papers we have counts for
6 papers
Enumeration of multi-rooted plane trees
Anwar Al Ghabra, K. Gopala Krishna, Patrick Labelle +1
We give closed form expressions for the numbers of multi-rooted plane trees with specified degrees of root vertices. This results in an infinite number of integer sequences some of…
Enumeration of N-rooted maps using quantum field theory
K. Krishna Gopala, Patrick Labelle, Vasilisa Shramchenko
A one-to-one correspondence is proved between the N-rooted ribbon graphs, or maps, with e edges and the (e-N+1)-loop Feynman diagrams of a certain quantum field theory. This result…
BKM superalgebras from counting dyons in N=4 supersymmetric type II compactifications
Suresh Govindarajan, Dileep P. Jatkar, K. Gopala Krishna
We study the degeneracy of quarter BPS dyons in N =4 type II compactifications of string theory. We find that the genus-two Siegel modular forms generating the degeneracies of the…
BKM Lie superalgebra for the Z_5 orbifolded CHL string
K. Gopala Krishna
We study the Z_5-orbifolding of the CHL string theory by explicitly constructing the modular form tilde{Phi}_2 generating the degeneracies of the 1/4-BPS states in the theory. Sinc…
BKM Lie superalgebras from dyon spectra in Z_N-CHL orbifolds for composite N
Suresh Govindarajan, K. Gopala Krishna
We show that the generating function of electrically charged 1/2-BPS states in N=4 supersymmetric Z_N-CHL orbifolds of the heterotic string on T^6 are given by multiplicative eta-p…
Generalized Kac-Moody Algebras from CHL dyons
Suresh Govindarajan, K Gopala Krishna
We provide evidence for the existence of a family of generalized Kac-Moody(GKM) superalgebras, G_N, whose Weyl-Kac-Borcherds denominator formula gives rise to a genus-two modular f…