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: "the well separated pair decomposition for balls"
  Abstract: Given a real number $t>1$, a geometric $t$-spanner is a geometric graph for a point set in $\mathbb{R}^d$ with straight lines between vertices such that the ratio of the shortest-path distance between every pair of vertices in the graph (with Euclidean edge lengths) to their actual Euclidean distance is at most $t$. An imprecise point set is modeled by a set $R$ of regions in $\mathbb{R}^d$. If one chooses a point in each region of $R$, then the resulting point set is called a precise instance of~$R$. An imprecise $t$-spanner for an imprecise point set $R$ is a graph $G=(R,E)$ such that for each precise instance $S$ of $R$, graph $G_S=(S,E_S)$, where $E_S$ is the set of edges corresponding to $E$, is a $t$-spanner. #R##N#In this paper, we show that, given a real number $t>1$, there is an imprecise point set $R$ of $n$ straight-line segments in the plane such that any imprecise $t$-spanner for $R$ has $\Omega(n^2)$ edges. Then, we propose an algorithm that computes a Well-Separated Pair Decomposition (WSPD) of size ${\cal O}(n)$ for a set of $n$ pairwise disjoint $d$-dimensional balls with arbitrary sizes. Given a real number $t>1$ and given a set of $n$ pairwise disjoint $d$-balls with arbitrary sizes, we use this WSPD to compute in ${\cal O}(n\log n+n/(t-1)^d)$ time an imprecise $t$-spanner with ${\cal O}(n/(t-1)^d)$ edges for balls.

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.CG(Computational Geometry)