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: "flow cut gaps for integer and fractional multiflows"
  Abstract: Consider a routing problem consisting of a demand graph H and a supply graph G. If the pair obeys the cut condition, then the flow-cut gap for this instance is the minimum value C such that there is a feasible multiflow for H if each edge of G is given capacity C. The flow-cut gap can be greater than 1 even when G is the (series-parallel) graph K_{2,3}. In this paper we are primarily interested in the "integer" flow-cut gap. What is the minimum value C such that there is a feasible integer valued multiflow for H if each edge of G is given capacity C? We conjecture that the integer flow-cut gap is quantitatively related to the fractional flow-cut gap. This strengthens the well-known conjecture that the flow-cut gap in planar and minor-free graphs is O(1) to suggest that the integer flow-cut gap is O(1). We give several results on non-trivial special classes of graphs supporting this conjecture and further explore the "primal" method for understanding flow-cut gaps. Our results include: #R##N#- Let G be obtained by series-parallel operations starting from an edge st, and consider orienting all edges in G in the direction from s to t. A demand is compliant if its endpoints are joined by a directed path in the resulting oriented graph. If the cut condition holds for a compliant instance and G+H is Eulerian, then an integral routing of H exists. #R##N#- The integer flow-cut gap in series-parallel graphs is 5. We also give an explicit class of instances that shows via elementary calculations that the flow-cut gap in series-parallel graphs is at least 2-o(1); this simplifies the proof by Lee and Raghavendra. #R##N#- The integer flow-cut gap in k-Outerplanar graphs is c^{O(k)} for some fixed constant c. #R##N#- A simple proof that the flow-cut gap is O(\log k^*) where k^* is the size of a node-cover in H; this was previously shown by G\"unl\"uk via a more intricate proof.

Connected through hyperedge HE-1 (induced by source paper "network coding gaps for completion times of multiple unicasts"):
  with members:
    - "flow cut gaps and face covers in planar graphs"
    - "new distributed algorithms in almost mixing time via transformations from parallel algorithms"
    - "faster distributed shortest path approximations via shortcuts"
    - "lower bounds for external memory integer sorting via network coding"
    - "low congestion shortcuts without embedding"
    - "cops robbers and threatening skeletons padded decomposition for minor free graphs"
    - "simple fast and deterministic gossip and rumor spreading"
    - "lexicographic products and the power of non linear network coding"

Connected through hyperedge HE-2 (induced by source paper "a face cover perspective to ell_1 embeddings of planar graphs"):
  with members:
    - "flow cut gaps and face covers in planar graphs"
    - "nearly eth tight algorithms for planar steiner tree with terminals on few faces"
    - "an exponential lower bound for cut sparsifiers in planar graphs"
    - "metric embedding via shortest path decompositions"
    - "refined vertex sparsifiers of planar graphs"
    - "on notions of distortion and an almost minimum spanning tree with constant average distortion"
    - "vertex sparsifiers new results from old techniques"
    - "cops robbers and threatening skeletons padded decomposition for minor free graphs"

Connected through hyperedge HE-3 (induced by source paper "flow cut gaps and face covers in planar graphs"):
  with members:
    - "nearly eth tight algorithms for planar steiner tree with terminals on few faces"
    - "metric embedding via shortest path decompositions"
    - "optimal stochastic planarization"

Connected through hyperedge HE-4 (induced by source paper "refined vertex sparsifiers of planar graphs"):
  with members:
    - "relaxed voronoi a simple framework for terminal clustering problems"
    - "steiner point removal with distortion o log k"
    - "improved guarantees for vertex sparsification in planar graphs"
    - "an exponential lower bound for cut sparsifiers in planar graphs"
    - "steiner point removal distant terminals don t really bother"
    - "graph minors for preserving terminal distances approximately lower and upper bounds"
    - "vertex sparsifiers new results from old techniques"
    - "on vertex sparsifiers with steiner nodes"

Connected through hyperedge HE-5 (induced by source paper "improved guarantees for vertex sparsification in planar graphs"):
  with members:
    - "steiner point removal with distortion o log k"
    - "steiner point removal distant terminals don t really bother"
    - "near optimal compression for the planar graph metric"
    - "reachability preservers new extremal bounds and approximation algorithms"
    - "a hierarchy of lower bounds for sublinear additive spanners"
    - "linear size distance preservers"
    - "graph minors for preserving terminal distances approximately lower and upper bounds"
    - "the 4 3 additive spanner exponent is tight"

Connected through hyperedge HE-6 (induced by source paper "new algorithms for maximum disjoint paths based on tree likeness"):
  with members:
    - "new hardness results for routing on disjoint paths"
    - "improved approximation for node disjoint paths in planar graphs"
    - "on routing disjoint paths in bounded treewidth graphs"
    - "maximum edge disjoint paths in k sums of graphs"
    - "a polylogarithimic approximation algorithm for edge disjoint paths with congestion 2"
    - "routing in undirected graphs with constant congestion"

Connected through hyperedge HE-7 (induced by source paper "vertex sparsifiers new results from old techniques"):
  with members:
    - "cutting corners cheaply or how to remove steiner points"
    - "towards 1 epsilon approximate flow sparsifiers"
    - "approximation algorithms and hardness of the k route cut problem"
    - "metric extension operators vertex sparsifiers and lipschitz extendability"
    - "interchanging distance and capacity in probabilistic mappings"

Connected through hyperedge HE-8 (induced by source paper "sparsest cut on bounded treewidth graphs algorithms and hardness results"):
  with members:
    - "constant factor lasserre integrality gaps for graph partitioning problems"
    - "approximating sparsest cut in graphs of bounded treewidth"
    - "a log n omega 1 integrality gap for the sparsest cut sdp"

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.DM(Discrete Mathematics)