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: "separator theorems for minor free and shallow minor free graphs with applications"
  Abstract: Alon, Seymour, and Thomas generalized Lipton and Tarjan's planar separator theorem and showed that a $K_h$-minor free graph with $n$ vertices has a separator of size at most $h^{3/2}\sqrt n$. They gave an algorithm that, given a graph $G$ with $m$ edges and $n$ vertices and given an integer $h\geq 1$, outputs in $O(\sqrt{hn}m)$ time such a separator or a $K_h$-minor of $G$. Plotkin, Rao, and Smith gave an $O(hm\sqrt{n\log n})$ time algorithm to find a separator of size $O(h\sqrt{n\log n})$. Kawarabayashi and Reed improved the bound on the size of the separator to $h\sqrt n$ and gave an algorithm that finds such a separator in $O(n^{1 + \epsilon})$ time for any constant $\epsilon > 0$, assuming $h$ is constant. This algorithm has an extremely large dependency on $h$ in the running time (some power tower of $h$ whose height is itself a function of $h$), making it impractical even for small $h$. We are interested in a small polynomial time dependency on $h$ and we show how to find an $O(h\sqrt{n\log n})$-size separator or report that $G$ has a $K_h$-minor in $O(\poly(h)n^{5/4 + \epsilon})$ time for any constant $\epsilon > 0$. We also present the first $O(\poly(h)n)$ time algorithm to find a separator of size $O(n^c)$ for a constant $c < 1$. As corollaries of our results, we get improved algorithms for shortest paths and maximum matching. Furthermore, for integers $\ell$ and $h$, we give an $O(m + n^{2 + \epsilon}/\ell)$ time algorithm that either produces a $K_h$-minor of depth $O(\ell\log n)$ or a separator of size at most $O(n/\ell + \ell h^2\log n)$. This improves the shallow minor algorithm of Plotkin, Rao, and Smith when $m = \Omega(n^{1 + \epsilon})$. We get a similar running time improvement for an approximation algorithm for the problem of finding a largest $K_h$-minor in a given graph.

Connected through hyperedge HE-1 (induced by source paper "diameter computation on h minor free graphs and graphs of bounded distance vc dimension"):
  with members:
    - "planar diameter via metric compression"
    - "fast diameter computation within split graphs"
    - "solving linear programs in the current matrix multiplication time"
    - "towards tight approximation bounds for graph diameter and eccentricities"
    - "multivariate analysis of orthogonal range searching and graph distances parameterized by treewidth"
    - "fully polynomial fpt algorithms for some classes of bounded clique width graphs"
    - "voronoi diagrams on planar graphs and computing the diameter in deterministic tilde o n 5 3 time"
    - "subquadratic algorithms for the diameter and the sum of pairwise distances in planar graphs"

Connected through hyperedge HE-2 (induced by source paper "good r divisions imply optimal amortised decremental biconnectivity"):
  with members:
    - "contracting a planar graph efficiently"
    - "fully dynamic connectivity in o log n log log n 2 amortized expected time"
    - "faster worst case deterministic dynamic connectivity"
    - "dynamic integer sets with optimal rank select and predecessor search"
    - "structured recursive separator decompositions for planar graphs in linear time"
    - "logarithmic lower bounds in the cell probe model"
    - "dynamic generators of topologically embedded graphs"

Connected through hyperedge HE-3 (induced by source paper "local search is a ptas for feedback vertex set in minor free graphs"):
  with members:
    - "local search yields approximation schemes for k means and k median in euclidean and minor free metrics"
    - "approximation algorithms for polynomial expansion and low density graphs"
    - "simple ptas s for families of graphs excluding a minor"
    - "solving the undirected feedback vertex set problem by local search"
    - "approximation algorithms for maximum independent set of pseudo disks"
    - "bidimensionality and eptas"
    - "eigenvalue bounds spectral partitioning and metrical deformations via flows"

Connected through hyperedge HE-4 (induced by source paper "parallel graph decompositions using random shifts"):
  with members:
    - "near linear work parallel sdd solvers low diameter decomposition and low stretch subgraphs"
    - "electrical flows laplacian systems and faster approximation of maximum flow in undirected graphs"
    - "faster approximate lossy generalized flow via interior point algorithms"
    - "nearly tight low stretch spanning trees"
    - "lower stretch spanning trees"

Connected through hyperedge HE-5 (induced by source paper "cops robbers and threatening skeletons padded decomposition for minor free graphs"):
  with members:
    - "randomly removing g handles at once"
    - "optimal stochastic planarization"
    - "eigenvalue bounds spectral partitioning and metrical deformations via flows"

Connected through hyperedge HE-6 (induced by source paper "grid minors in damaged grids"):
  with members:
    - "approximation algorithms for euler genus and related problems"
    - "polynomial bounds for the grid minor theorem"
    - "bandwidth and pathwidth of three dimensional grids"

Connected through hyperedge HE-7 (induced by source paper "approximate maximum flow on separable undirected graphs"):
  with members:
    - "multiple source multiple sink maximum flow in directed planar graphs in near linear time"
    - "runtime guarantees for regression problems"
    - "a nearly mlogn time solver for sdd linear systems"
    - "faster approximation schemes for fractional multicommodity flow problems via dynamic graph algorithms"
    - "approaching optimality for solving sdd systems"
    - "electrical flows laplacian systems and faster approximation of maximum flow in undirected graphs"
    - "graph sparsification by effective resistances"
    - "nearly linear time algorithms for preconditioning and solving symmetric diagonally dominant linear systems"

Connected through hyperedge HE-8 (induced by source paper "structured recursive separator decompositions for planar graphs in linear time"):
  with members:
    - "linear space approximate distance oracles for planar bounded genus and minor free graphs"
    - "exact distance oracles for planar graphs"
    - "shortest paths in planar graphs with real lengths in o n log 2n log log n time"
    - "eigenvalue bounds spectral partitioning and metrical deformations via flows"
    - "maintaining information in fully dynamic trees with top trees"
    - "dynamic generators of topologically embedded graphs"

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)