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: "new alpha beta spanners and hopsets"
  Abstract: An $f(d)$-spanner of an unweighted $n$-vertex graph $G=(V,E)$ is a subgraph $H$ satisfying that $dist_H(u, v)$ is at most $f(dist_G(u, v))$ for every $u,v \in V$. We present new spanner constructions that achieve a nearly optimal stretch of $O(\lceil k /d \rceil)$ for any distance value $d \in [1,k^{1-o(1)}]$, and $d \geq k^{1+o(1)}$. We show the following: #R##N#1. There exists an $f(d)$-spanner $H \subseteq G$ with $f(d)\leq 7k$ for any $d \in [1,\sqrt{k}/2]$ with expected size $O_{k}(n^{1+1/k})$. This in particular gives $(\alpha,\beta)$ spanners with $\alpha=O(\sqrt{k})$ and $\beta=O(k)$. #R##N#2. For any $\epsilon \in (0,1/2]$, there exists an $(\alpha,\beta)$-spanner with $\alpha=O(k^{\epsilon})$, $\beta=O_{\epsilon}(k)$ and of expected size $O_{k}(n^{1+1/k})$. This implies a stretch of $O(\lceil k/d \rceil)$ for any $d \in [\sqrt{k}/2, k^{1-\epsilon}]$, and for every $d\geq k^{1+\epsilon}$. In particular, it provides a constant stretch already for vertex pairs at distance $k^{1+o(1)}$ (improving upon $d=(\log k)^{\log k}$ that was known before). Up to the $o(1)$ factor in the exponent, and the constant factor in the stretch, this is the best possible by the girth argument. #R##N#3. For any $\epsilon \in (0,1)$, there is a $(3+\epsilon, \beta)$-spanner with $\beta=O_{\epsilon}(k^{\log(3+8/\epsilon)})$. #R##N#We also consider the related graph concept of hopsets introduced by [Cohen, J. ACM '00]. We present a new family of $(\alpha,\beta)$ hopsets with $\widetilde{O}(k \cdot n^{1+1/k})$ edges and $\alpha \cdot \beta=O(k)$. Most notably, we show a construction of $(3+\epsilon,\beta)$ hopset with $\widetilde{O}_{\epsilon}(n)$ edges and hop-bound of $\beta=O_{\epsilon}((\log n)^{\log(3+9/\epsilon)})$, improving upon the state-of-the-art hop-bound of $\beta=O(\log\log n)^{\log \log n}$ by [Elkin-Neiman, '17] and [Huang-Pettie, '17]

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)