human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "petiga high performance isogeometric analysis"
  Abstract: In this paper we present a code framework for isogeometric analysis which we call PetIGA. We base this framework heavily on components from PETSc, a scientific library geared toward implementing scalable solvers needed for approximating solutions to partial differential equations. Our open source library can be used to assemble matrices and vectors which, for this release, come from a Galerkin weak form, discretized with the Non-Uniform Rational B-spline (NURBS) basis. We also detail the computation of these basis functions as well as how higher-order derivatives may be pushed forward for use in isoparametric mappings. Finally, we show performance results on a variety of nonlinear and time dependent problems illustrating the flexibility and efficiency of our framework. We solve large deformation hyper-elasticity, the Cahn-Hilliard equation, the Navier-Stokes-Korteweg equation, as well as Navier-Stokes in context of turbulent flow modeled with the variational multiscale method.

Connected through hyperedge HE-1 (induced by source paper "fast multipole preconditioners for sparse matrices arising from elliptic equations"):
  with members:
    - "a fast block low rank dense solver with applications to finite element matrices"
    - "an fmm based on dual tree traversal for many core architectures"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.MS(Mathematical Software)