Papers
Topics
Authors
Recent
Assistant
AI Research Assistant
Well-researched responses based on relevant abstracts and paper content.
Custom Instructions Pro
Preferences or requirements that you'd like Emergent Mind to consider when generating responses.
Gemini 2.5 Flash
Gemini 2.5 Flash 160 tok/s
Gemini 2.5 Pro 49 tok/s Pro
GPT-5 Medium 39 tok/s Pro
GPT-5 High 28 tok/s Pro
GPT-4o 98 tok/s Pro
Kimi K2 196 tok/s Pro
GPT OSS 120B 437 tok/s Pro
Claude Sonnet 4.5 38 tok/s Pro
2000 character limit reached

On two notions of total positivity for generalized partial flag varieties of classical Lie types (2410.11804v2)

Published 15 Oct 2024 in math.CO, math.AG, and math.RT

Abstract: For Grassmannians, Lusztig's notion of total positivity coincides with positivity of the Plucker coordinates. This coincidence underpins the rich interaction between matroid theory, tropical geometry, and the theory of total positivity. Bloch and Karp furthermore characterized the (type A) partial flag varieties for which the two notions of positivity similarly coincide. We characterize the symplectic (type C) and odd-orthogonal (type B) partial flag varieties for which Lusztig's total positivity coincides with Plucker positivity.

Definition Search Book Streamline Icon: https://streamlinehq.com
References (36)
  1. Grassmannian geometry of scattering amplitudes. Cambridge University Press, Cambridge, 2016.
  2. Positively oriented matroids are realizable. Journal of the European Mathematical Society, pages 815–833, 2017.
  3. On the generating functions of totally positive sequences. I. J. Analyse Math., 2:93–103, 1952.
  4. Combinatorics of Coxeter Groups. Graduate Texts in Mathematics. Springer Berlin, Heidelberg, 2005.
  5. Polyhedral and tropical geometry of flag positroids. Algebra Number Theory, 18(7):1333–1374, 2024.
  6. Coxeter matroids, volume 216 of Progress in Mathematics. Birkhäuser Boston, Inc., Boston, MA, 2003.
  7. On two notions of total positivity for partial flag varieties. Adv. Math., 414:Paper No. 108855, 24, 2023.
  8. Sara Billey and V. Lakshmibai. Singular loci of Schubert varieties, volume 182 of Progress in Mathematics. Birkhäuser Boston, Inc., Boston, MA, 2000.
  9. The tropical symplectic Grassmannian. Int. Math. Res. Not. IMRN, 2023(2):1036–1072, 2023.
  10. Jonathan Boretsky. Totally Nonnegative Tropical Flags and the Totally Nonnegative Flag Dressian, 2023.
  11. Nicolas Chevalier. Total positivity criteria for partial flag varieties. J. Algebra, 348:402–415, 2011.
  12. Colin W. Cryer. The L⁢U𝐿𝑈LUitalic_L italic_U-factorization of totally positive matrices. Linear Algebra Appl., 7:83–92, 1973.
  13. Colin W. Cryer. Some properties of totally positive matrices. Linear Algebra Appl., 15(1):1–25, 1976.
  14. Vinay V. Deodhar. On some geometric aspects of Bruhat orderings. I. A finer decomposition of Bruhat cells. Invent. Math., 79(3):499–511, 1985.
  15. Vinay V. Deodhar. On some geometric aspects of Bruhat orderings. II. The parabolic analogue of Kazhdan-Lusztig polynomials. J. Algebra, 111(2):483–506, 1987.
  16. Totally nonnegative matrices. Princeton Series in Applied Mathematics. Princeton University Press, Princeton, NJ, 2011.
  17. Sergey Fomin. Total positivity and cluster algebras. In Proceedings of the International Congress of Mathematicians. Volume II, pages 125–145. Hindustan Book Agency, New Delhi, 2010.
  18. Total positivity: tests and parametrizations. Math. Intelligencer, 22(1):23–33, 2000.
  19. Ising model and the positive orthogonal Grassmannian. Duke Math. J., 169(10):1877–1942, 2020.
  20. Positivity and higher Teichmüller theory. In European Congress of Mathematics, pages 289–310. Eur. Math. Soc., Zürich, 2018.
  21. James E. Humphreys. Reflection groups and Coxeter groups, volume 29 of Cambridge Studies in Advanced Mathematics. Cambridge University Press, Cambridge, 1990.
  22. Generalized permutahedra and positive flag dressians. Int. Math. Res. Not. IMRN, 2023(19):16748–16777, 2023.
  23. Rachel Karpman. Total positivity for the Lagrangian Grassmannian. Adv. in Appl. Math., 98:25–76, 2018.
  24. Thomas Lam. Totally nonnegative grassmannian and grassmann polytopes. Current Developments in Mathematics, pages 51–150, 2014.
  25. Charles Loewner. On totally positive matrices. Math. Z., 63:338–340, 1955.
  26. G. Lusztig. Total positivity in reductive groups. In Lie theory and geometry, volume 123 of Progr. Math., pages 531–568. Birkhäuser Boston, Boston, MA, 1994.
  27. G. Lusztig. Total positivity in partial flag manifolds. Represent. Theory, 2:70–78, 1998.
  28. R. J. Marsh and K. Rietsch. Parametrizations of flag varieties. Represent. Theory, 8:212–242, 2004.
  29. Alexander Postnikov. Total positivity, grassmannians, and networks, 2006.
  30. The m=2𝑚2m=2italic_m = 2 amplituhedron and the hypersimplex: signs, clusters, tilings, Eulerian numbers. Commun. Am. Math. Soc., 3:329–399, 2023.
  31. Konstanze Christina Rietsch. Total positivity and real flag varieties. ProQuest LLC, Ann Arbor, MI, 1998. Thesis (Ph.D.)–Massachusetts Institute of Technology.
  32. Felipe Rincón. Isotropical linear spaces and valuated delta-matroids. In 23rd International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2011), volume AO of Discrete Math. Theor. Comput. Sci. Proc., pages 801–812. Assoc. Discrete Math. Theor. Comput. Sci., Nancy, 2011.
  33. The tropical totally positive Grassmannian. J. Algebraic Combin., 22(2):189–210, 2005.
  34. The positive Dressian equals the positive tropical Grassmannian. Trans. Amer. Math. Soc. Ser. B, 8:330–353, 2021.
  35. Network parametrizations for the Grassmannian. Algebra Number Theory, 7(9):2275–2311, 2013.
  36. A. M. Whitney. A reduction theorem for totally positive matrices. J. Analyse Math., 2:88–92, 1952.

Summary

We haven't generated a summary for this paper yet.

Dice Question Streamline Icon: https://streamlinehq.com

Open Problems

We haven't generated a list of open problems mentioned in this paper yet.

Lightbulb Streamline Icon: https://streamlinehq.com

Continue Learning

We haven't generated follow-up questions for this paper yet.

List To Do Tasks Checklist Streamline Icon: https://streamlinehq.com

Collections

Sign up for free to add this paper to one or more collections.

X Twitter Logo Streamline Icon: https://streamlinehq.com

Tweets

This paper has been mentioned in 1 tweet and received 0 likes.

Upgrade to Pro to view all of the tweets about this paper: