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: "ramanujan graphs in polynomial time"
  Abstract: The recent work [MSS15a] by Marcus, Spielman and Srivastava proves the existence of bipartite Ramanujan (multi)graphs of all degrees and all sizes. However, that paper did not provide a polynomial time algorithm to actually compute such graphs. Here, we provide a polynomial time algorithm to compute certain expected characteristic polynomials related to this construction. This leads to a deterministic polynomial time algorithm to compute bipartite Ramanujan (multi)graphs of all degrees and all sizes. Note: after writing this paper, the author became aware that others have independently produced this result, but does not know any specifics.

Connected through hyperedge HE-1 (induced by source paper "explicit near ramanujan graphs of every degree"):
  with members:
    - "the sdp value for random two eigenvalue csps"
    - "the threshold for sdp refutation of random regular nae 3sat"
    - "graph zeta function in the bethe free energy and loopy belief propagation"
    - "a proof of alon s second eigenvalue conjecture and related problems"

Connected through hyperedge HE-2 (induced by source paper "semantic security and the second largest eigenvalue of biregular graphs"):
  with members:
    - "the mac resolvability region semantic security and its operational implications"
    - "secure multiplex coding with dependent and non uniform multiple messages"
    - "a channel under simultaneous jamming and eavesdropping attack correlated random coding capacities under strong secrecy criteria"
    - "arbitrarily varying wiretap channels with type constrained states"
    - "semantic security capacity for wiretap channels of type ii"
    - "achieving secrecy capacity of the gaussian wiretap channel with polar lattices"
    - "universal hashing for information theoretic security"
    - "renyi divergence and kullback leibler divergence"

Connected through hyperedge HE-3 (induced by source paper "gradient coding from cyclic mds codes and expander graphs"):
  with members:
    - "speeding up distributed machine learning using codes"
    - "lagrange coded computing optimal design for resiliency security and privacy"
    - "near optimal straggler mitigation for distributed gradient methods"
    - "short dot computing large linear transforms distributedly using coded short dot products"
    - "revisiting distributed synchronous sgd"
    - "improving distributed gradient descent using reed solomon codes"
    - "a fundamental tradeoff between computation and communication in distributed computing"
    - "a unified coding framework for distributed computing with straggling servers"

Connected through hyperedge HE-4 (induced by source paper "an alon boppana type bound for weighted graphs and lowerbounds for spectral sparsification"):
  with members:
    - "a proof of alon s second eigenvalue conjecture and related problems"
    - "nearly linear time algorithms for graph partitioning graph sparsification and solving linear systems"

Connected through hyperedge HE-5 (induced by source paper "approximating the largest root and applications to interlacing families"):
  with members:
    - "computing the independence polynomial in shearer s region for the lll"

Connected through hyperedge HE-6 (induced by source paper "invertibility and largest eigenvalue of symmetric matrix signings"):
  with members:
    - "on the expansion of group based lifts"

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.DS(Data Structures and Algorithms)