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: "capacity achieving input distributions in nondispersive optical fibers"
  Abstract: This paper investigates the discrete-time per-sample model of the zero-dispersion optical fiber. It is shown that any capacity-achieving input distribution has (continuous) uniform phase and discrete amplitude with a finite number of mass points. This result holds when the input is subject to general input cost constraints that include peak power constraint and joint average and peak power constraint.

Connected through hyperedge HE-1 (induced by source paper "autocorrelation function for dispersion free fiber channels with distributed amplification"):
  with members:
    - "upper bound on the capacity of a cascade of nonlinear and noisy channels"
    - "capacity bounds for discrete time amplitude constrained additive white gaussian noise channels"
    - "optimal input signal distribution and per sample mutual information for nondispersive nonlinear optical fiber channel in large snr limit"
    - "on continuous time white phase noise channels"
    - "on the per sample capacity of nondispersive optical fibers"
    - "calculation of mutual information for partially coherent gaussian channels with applications to fiber optics"

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.IT(Information Theory)