Abstract
If G is a graph with vertex set V, let \({{\mathrm{Conf}}}_n^{{{\mathrm{sink}}}}(G,V)\) be the space of n-tuples of points on G, which are only allowed to overlap on elements of V. We think of \({{\mathrm{Conf}}}_n^{{{\mathrm{sink}}}}(G,V)\) as a configuration space of points on G, where points are allowed to collide on vertices. In this paper, we attempt to understand these spaces from two separate, but closely related, perspectives. Using techniques of combinatorial topology we compute the fundamental groups and homology groups of \({{\mathrm{Conf}}}_n^{{{\mathrm{sink}}}}(G,V)\) in the case where G is a tree. Next, we use techniques of asymptotic algebra to prove statements about \({{\mathrm{Conf}}}_n^{{{\mathrm{sink}}}}(G,V)\), for general graphs G, whenever n is sufficiently large. It is proven that, for general graphs, the homology groups exhibit generalized representation stability in the sense of Ramos (arXiv:1606.02673, 2016).
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References
Abrams, A.: Configuration Spaces and Braid Groups of Graphs. PhD Thesis. http://home.wlu.edu/~abramsa/publications/thesis.ps
Barnett, K., Farber, M.: Topology of configuration space of two particles on a graph. I. Algebr. Geom. Topol. 9(1), 593–624 (2009). arXiv:0903.2180
Charney, R.: An introduction to right-angled Artin groups. R. Geom. Dedicata 125, 141–158 (2007). http://people.brandeis.edu/~charney/papers/RAAGfinal.pdf
Chettih, S.: Dancing in the Stars: Topology of Non-$K$-Equal Configuration Spaces of Graphs. PhD Thesis. University of Oregon (2016)
Chettih, S., Lütgehetmann, D.: The homology of configuration spaces of trees with loops. Algebr. Geom. Topol. 18, 2443–2469 (2018). arXiv:1612.08290
Church, T.: Homological stability for configuration spaces of manifolds. Invent. Math. 188(2), 465–504 (2012). arXiv:1103.2441
Church, T., Ellenberg, J.S., Farb, B., Nagpal, R.: FI-modules over Noetherian rings. Geom. Topol. 18(5), 2951–2984 (2014)
Church, T., Ellenberg, J.S., Farb, B.: FI-modules and stability for representations of symmetric groups. Duke Math. J. 164(9), 1833–1910 (2015)
Church, T., Farb, B.: Representation theory and homological stability. Adv. Math. 245, 250–314 (2013)
Cohen, F., Pakianathan, J.: Configuration spaces and braid groups. Course Notes. http://web.math.rochester.edu/people/faculty/jonpak/newbraid.pdf
Ellenberg, J.S., Wiltshire-Gordon, J.D.: Algebraic structures on cohomology of configuration spaces of manifolds with flows (2015). arXiv:1508.02430
Fadell, E.R., Husseini, S.Y.: Geometry and Topology of Configuration Spaces. Springer Monographs in Mathematics. Springer, Berlin (2001)
Farber, M.: Invitation to Topological Robotics. Zürich Lectures in Advanced Mathematics. European Mathematical Society, Zürich (2008)
Farley, D.: Homology of tree braid groups. In: Grigorchuk, R., et al. (eds.) Topological and Asymptotic Aspects of Group Theory. Contemporary Mathematics, vol. 394, pp. 101–112. American Mathematical Society, Providence (2006). http://www.users.miamioh.edu/farleyds/grghom.pdf
Farley, D., Sabalka, L.: Discrete Morse theory and graph braid groups. Algebr. Geom. Topol. 5, 1075–1109 (2005). http://www.users.miamioh.edu/farleyds/FS1.pdf
Forman, R.: Morse theory for cell complexes. Adv. Math. 134(1), 90–145 (1998)
Forman, R.: A user’s guide to discrete Morse theory. Séminaire Lotharingien de Combinatoire 48 (2002). http://www.emis.de/journals/SLC/wpapers/s48forman.pdf
Ghrist, R.: Configuration spaces and braid groups on graphs in robotics. In: Gilman, J., Menasco, W.M., Lin, X.-S. (eds.) Knots, Braids, and Mapping Class Groups: Papers Dedicated to Joan S. Birman. AMS/IP Studies in Advanced Mathematics, vol. 24, pp. 29–40. American Mathematical Society, Providence (2001). https://www.math.upenn.edu/~ghrist/preprints/birman.pdf
Hersh, P., Reiner, V.: Representation stability for cohomology of configuration spaces in ${\mathbb{R}}^d$. Int. Math. Res. Not. IMRN 2017(5), 1433–1486 (2017). arXiv:1505.04196
Kim, J.H., Ko, K.H., Park, H.W.: Graph braid groups and right-angled Artin groups. Trans. Am. Math. Soc. 364(1), 309–360 (2012). arXiv:0805.0082
Ko, K.H., Park, H.W.: Characteristics of graph braid groups. Discrete Comput. Geom. 48(4), 915–963 (2012). arXiv:1101.2648
Lütgehetmann, D.: Configuration Spaces of Graphs. Masters Thesis. http://luetge.userpage.fu-berlin.de/pdfs/masters-thesis-luetgehetmann.pdf
Lütgehetmann, D.: Representation stability for configuration spaces of graphs (2017). arXiv:1701.03490
Maguire, M.: Computing cohomology of configuration spaces. With an appendix by M. Christie and D. Francour (2016). arXiv:1612.06314
Miller, J., Wilson, J.C.H.: Higher order representation stability and ordered configuration spaces of manifolds (2016). arXiv:1611.01920
Ramos, E.: Generalized representation stability and $\text{ FI }_{d}$-modules. Proc. Amer. Math. Soc. 145(11), 4647–4660 (2017)
Ramos, E.: Stability phenomena in the homology of tree braid groups. Algebr. Geom. Topol. 18(4), 2305–2337 (2018). arXiv:1609.05611
Sam, S.V.: Syzygies of bounded rank symmetric tensors are generated in bounded degree. Math. Ann. 368(3–4), 1095–1108 (2017). arXiv:1608.01722
Sam, S.V.: Ideals of bounded rank symmetric tensors are generated in bounded degree. Invent. Math. 207(1), 1–21 (2017). arXiv:1510.04904
Sam, S.V., Snowden, A.: Gröbner methods for representations of combinatorial categories. J. Am. Math. Soc. 30(1), 159–203 (2017). arXiv:1409.1670
Sam, S.V., Snowden, A.: GL-equivariant modules over polynomial rings in infinitely many variables. II (2017). arXiv:1703.04516
Snowden, A.: Syzygies of Segre embeddings and $\Delta $-modules. Duke Math. J. 162(2), 225–277 (2013). arXiv:1006.5248
Acknowledgements
The author would like to send thanks to Jordan Ellenberg, John Wiltshire-Gordon, Jennifer Wilson and Graham White for various useful conversations during the writing and conception of this work. The author would also like to send very special thanks to Steven Sam for his support during the initial stages of this work. The author would like to send thanks to the two anonymous referees, whose various suggestions greatly improved the overall quality of this work. Finally, the author would like to acknowledge the generous support of the NSF via the grant DMS-1502553.
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The author was supported by NSF grant DMS-1502553.
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Ramos, E. Configuration Spaces of Graphs with Certain Permitted Collisions. Discrete Comput Geom 62, 912–944 (2019). https://doi.org/10.1007/s00454-018-0045-6
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DOI: https://doi.org/10.1007/s00454-018-0045-6