Skip to main content
Log in

Configuration Spaces of Graphs with Certain Permitted Collisions

  • Published:
Discrete & Computational Geometry Aims and scope Submit manuscript

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).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

We’re sorry, something doesn't seem to be working properly.

Please try refreshing the page. If that doesn't work, please contact support so we can address the problem.

References

  1. Abrams, A.: Configuration Spaces and Braid Groups of Graphs. PhD Thesis. http://home.wlu.edu/~abramsa/publications/thesis.ps

  2. 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

    Article  MathSciNet  Google Scholar 

  3. Charney, R.: An introduction to right-angled Artin groups. R. Geom. Dedicata 125, 141–158 (2007). http://people.brandeis.edu/~charney/papers/RAAGfinal.pdf

  4. Chettih, S.: Dancing in the Stars: Topology of Non-$K$-Equal Configuration Spaces of Graphs. PhD Thesis. University of Oregon (2016)

  5. Chettih, S., Lütgehetmann, D.: The homology of configuration spaces of trees with loops. Algebr. Geom. Topol. 18, 2443–2469 (2018). arXiv:1612.08290

    Article  MathSciNet  Google Scholar 

  6. Church, T.: Homological stability for configuration spaces of manifolds. Invent. Math. 188(2), 465–504 (2012). arXiv:1103.2441

    Article  MathSciNet  Google Scholar 

  7. Church, T., Ellenberg, J.S., Farb, B., Nagpal, R.: FI-modules over Noetherian rings. Geom. Topol. 18(5), 2951–2984 (2014)

    Article  MathSciNet  Google Scholar 

  8. Church, T., Ellenberg, J.S., Farb, B.: FI-modules and stability for representations of symmetric groups. Duke Math. J. 164(9), 1833–1910 (2015)

    Article  MathSciNet  Google Scholar 

  9. Church, T., Farb, B.: Representation theory and homological stability. Adv. Math. 245, 250–314 (2013)

    Article  MathSciNet  Google Scholar 

  10. Cohen, F., Pakianathan, J.: Configuration spaces and braid groups. Course Notes. http://web.math.rochester.edu/people/faculty/jonpak/newbraid.pdf

  11. Ellenberg, J.S., Wiltshire-Gordon, J.D.: Algebraic structures on cohomology of configuration spaces of manifolds with flows (2015). arXiv:1508.02430

  12. Fadell, E.R., Husseini, S.Y.: Geometry and Topology of Configuration Spaces. Springer Monographs in Mathematics. Springer, Berlin (2001)

    Book  Google Scholar 

  13. Farber, M.: Invitation to Topological Robotics. Zürich Lectures in Advanced Mathematics. European Mathematical Society, Zürich (2008)

  14. 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

  15. 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

  16. Forman, R.: Morse theory for cell complexes. Adv. Math. 134(1), 90–145 (1998)

    Article  MathSciNet  Google Scholar 

  17. 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

  18. 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

  19. 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

  20. 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

  21. Ko, K.H., Park, H.W.: Characteristics of graph braid groups. Discrete Comput. Geom. 48(4), 915–963 (2012). arXiv:1101.2648

  22. Lütgehetmann, D.: Configuration Spaces of Graphs. Masters Thesis. http://luetge.userpage.fu-berlin.de/pdfs/masters-thesis-luetgehetmann.pdf

  23. Lütgehetmann, D.: Representation stability for configuration spaces of graphs (2017). arXiv:1701.03490

  24. Maguire, M.: Computing cohomology of configuration spaces. With an appendix by M. Christie and D. Francour (2016). arXiv:1612.06314

  25. Miller, J., Wilson, J.C.H.: Higher order representation stability and ordered configuration spaces of manifolds (2016). arXiv:1611.01920

  26. Ramos, E.: Generalized representation stability and $\text{ FI }_{d}$-modules. Proc. Amer. Math. Soc. 145(11), 4647–4660 (2017)

    Article  MathSciNet  Google Scholar 

  27. Ramos, E.: Stability phenomena in the homology of tree braid groups. Algebr. Geom. Topol. 18(4), 2305–2337 (2018). arXiv:1609.05611

    Article  MathSciNet  Google Scholar 

  28. 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

    Article  MathSciNet  Google Scholar 

  29. Sam, S.V.: Ideals of bounded rank symmetric tensors are generated in bounded degree. Invent. Math. 207(1), 1–21 (2017). arXiv:1510.04904

    Article  MathSciNet  Google Scholar 

  30. Sam, S.V., Snowden, A.: Gröbner methods for representations of combinatorial categories. J. Am. Math. Soc. 30(1), 159–203 (2017). arXiv:1409.1670

    Article  Google Scholar 

  31. Sam, S.V., Snowden, A.: GL-equivariant modules over polynomial rings in infinitely many variables. II (2017). arXiv:1703.04516

  32. Snowden, A.: Syzygies of Segre embeddings and $\Delta $-modules. Duke Math. J. 162(2), 225–277 (2013). arXiv:1006.5248

    Article  MathSciNet  Google Scholar 

Download references

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.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Eric Ramos.

Additional information

Editor in Charge: Kenneth Clarkson

The author was supported by NSF grant DMS-1502553.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

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

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00454-018-0045-6

Keywords

Mathematics Subject Classification

Navigation