Real and Positive Tropicalizations of Symmetric Determinantal Varieties
Algebraic Combinatorics, Volume 9 (2026) no. 1, pp. 1-19

We study real and positive tropicalizations of the varieties of low rank symmetric matrices over real or complex Puiseux series. We show that real tropicalization coincides with complex tropicalization for rank two and corank one cases. We also show that the two notions of positive tropicalization introduced by Speyer and Williams coincide for symmetric rank two matrices, but they differ for symmetric corank one matrices.

Received:
Revised:
Accepted:
Published online:
DOI: 10.5802/alco.462
Classification: 14T15, 14P05, 14M12, 05E14, 15B33
Keywords: ranks of tropical matrices, positive tropicalization, symmetric matrices, determinantal varieties, bicolored trees

Al Ahmadieh, Abeer  1 ; Cai, May  2 ; Yu, Josephine  2

1 School of Mathematics, American University of Sharjah, Sharjah 26666, UAE
2 School of Mathematics, Georgia Tech, Atlanta, GA 30332, USA
License: CC-BY 4.0
Copyrights: The authors retain unrestricted copyrights and publishing rights
@article{ALCO_2026__9_1_1_0,
     author = {Al Ahmadieh, Abeer and Cai, May and Yu, Josephine},
     title = {Real and {Positive} {Tropicalizations} of {Symmetric} {Determinantal} {Varieties}},
     journal = {Algebraic Combinatorics},
     pages = {1--19},
     year = {2026},
     publisher = {The Combinatorics Consortium},
     volume = {9},
     number = {1},
     doi = {10.5802/alco.462},
     language = {en},
     url = {https://alco.centre-mersenne.org/articles/10.5802/alco.462/}
}
TY  - JOUR
AU  - Al Ahmadieh, Abeer
AU  - Cai, May
AU  - Yu, Josephine
TI  - Real and Positive Tropicalizations of Symmetric Determinantal Varieties
JO  - Algebraic Combinatorics
PY  - 2026
SP  - 1
EP  - 19
VL  - 9
IS  - 1
PB  - The Combinatorics Consortium
UR  - https://alco.centre-mersenne.org/articles/10.5802/alco.462/
DO  - 10.5802/alco.462
LA  - en
ID  - ALCO_2026__9_1_1_0
ER  - 
%0 Journal Article
%A Al Ahmadieh, Abeer
%A Cai, May
%A Yu, Josephine
%T Real and Positive Tropicalizations of Symmetric Determinantal Varieties
%J Algebraic Combinatorics
%D 2026
%P 1-19
%V 9
%N 1
%I The Combinatorics Consortium
%U https://alco.centre-mersenne.org/articles/10.5802/alco.462/
%R 10.5802/alco.462
%G en
%F ALCO_2026__9_1_1_0
Al Ahmadieh, Abeer; Cai, May; Yu, Josephine. Real and Positive Tropicalizations of Symmetric Determinantal Varieties. Algebraic Combinatorics, Volume 9 (2026) no. 1, pp. 1-19. doi: 10.5802/alco.462

[1] Ahmed, Maya Mohsin Polytopes of magic labelings of graphs and the faces of the Birkhoff polytope, Ann. Comb., Volume 12 (2008) no. 3, pp. 241-269 | DOI | MR | Zbl

[2] Allamigeon, Xavier; Gaubert, Stéphane; Skomra, Mateusz Tropical spectrahedra, Discrete Comput. Geom., Volume 63 (2020) no. 3, pp. 507-548 | DOI | MR | Zbl

[3] Ardila, Federico A tropical morphism related to the hyperplane arrangement of the complete bipartite graph (2004) | arXiv | Zbl

[4] Bernstein, Daniel Irving Completion of tree metrics and rank 2 matrices, Linear Algebra Appl., Volume 533 (2017), pp. 1-13 | DOI | MR | Zbl

[5] Billera, Louis J.; Sarangarajan, A. The combinatorics of permutation polytopes, Formal power series and algebraic combinatorics (New Brunswick, NJ, 1994) (DIMACS Ser. Discrete Math. Theoret. Comput. Sci.), Volume 24, Amer. Math. Soc., Providence, RI, 1996, pp. 1-23 | DOI | MR | Zbl

[6] Brandenburg, Marie-Charlotte; Loho, Georg; Sinn, Rainer Tropical positivity and determinantal varieties, Algebr. Comb., Volume 6 (2023) no. 4, pp. 999-1040 | MR | DOI | Numdam | Zbl

[7] Brandenburg, Marie-Charlotte; Loho, Georg; Sinn, Rainer Corrigendum to “Tropical Positivity and Determinantal Varieties”, Algebr. Comb., Volume 7 (2024) no. 3, pp. 749-751 | DOI | Numdam | Zbl | MR

[8] Brualdi, Richard A.; Cao, Lei Symmetric, Hankel-symmetric, and centrosymmetric doubly stochastic matrices, Acta Math. Vietnam., Volume 43 (2018) no. 4, pp. 675-700 | DOI | MR | Zbl

[9] Cai, May; Lee, Kisun; Yu, Josephine The tropical variety of symmetric rank 2 matrices, Linear Algebra Appl., Volume 720 (2025), pp. 50-71 | DOI | MR | Zbl

[10] Cartwright, Dustin; Chan, Melody Three notions of tropical rank for symmetric matrices, Combinatorica, Volume 32 (2012) no. 1, pp. 55-84 | DOI | MR | Zbl

[11] Develin, Mike; Santos, Francisco; Sturmfels, Bernd On the rank of a tropical matrix, Combinatorial and computational geometry (Math. Sci. Res. Inst. Publ.), Volume 52, Cambridge Univ. Press, Cambridge, 2005, pp. 213-242 | MR | DOI | Zbl

[12] Dodgson, Charles Lutwidge Condensation of determinants, being a new and brief method for computing their arithmetical values, Proc. R. Soc. Lond., Volume 15 (1867), pp. 150-155 | DOI

[13] Fink, Alex; Rincón, Felipe Stiefel tropical linear spaces, J. Combin. Theory Ser. A, Volume 135 (2015), pp. 291-331 | DOI | MR | Zbl

[14] Hultman, Axel; Jonsson, Jakob The topology of the space of matrices of Barvinok rank two, Beiträge Algebra Geom., Volume 51 (2010) no. 2, pp. 373-390 | MR | Zbl

[15] Jell, Philipp; Scheiderer, Claus; Yu, Josephine Real tropicalization and analytification of semialgebraic sets, Int. Math. Res. Not. IMRN, Volume 2022 (2022) no. 2, pp. 928-958 ([Initially appeared as 2021, no. 24, 19178–19208]) | DOI | MR | Zbl

[16] Maclagan, Diane; Sturmfels, Bernd Introduction to tropical geometry, Graduate Studies in Mathematics, 161, American Mathematical Society, Providence, RI, 2015, xii+363 pages | DOI | MR | Zbl

[17] Markwig, Hannah; Yu, Josephine The space of tropically collinear points is shellable, Collect. Math., Volume 60 (2009) no. 1, pp. 63-77 | DOI | MR | Zbl

[18] Oxley, James Matroid theory, Oxford Graduate Texts in Mathematics, 21, Oxford University Press, Oxford, 2011, xiv+684 pages | DOI | MR | Zbl

[19] Pachter, Lior; Sturmfels, Bernd Tropical geometry of statistical models, Proc. Natl. Acad. Sci. USA, Volume 101 (2004) no. 46, pp. 16132-16137 | DOI | MR | Zbl

[20] Rose, Kemal; Telek, Máté L. Computing positive tropical varieties and lower bounds on the number of positive roots, J. Symbolic Comput., Volume 132 (2026), Paper no. 102477, 26 pages | DOI | MR | Zbl

[21] Shitov, Yaroslav On the nonnegative ranks of matrices in Puiseux series fields, Adv. in Appl. Math., Volume 170 (2025), Paper no. 102916, 6 pages | DOI | MR | Zbl

[22] Speyer, David; Williams, Lauren The tropical totally positive Grassmannian, J. Algebraic Combin., Volume 22 (2005) no. 2, pp. 189-210 | DOI | MR | Zbl

[23] Tabera, Luis Felipe On real tropical bases and real tropical discriminants, Collect. Math., Volume 66 (2015) no. 1, pp. 77-92 | DOI | MR | Zbl

[24] Vinzant, Cynthia Real radical initial ideals, J. Algebra, Volume 352 (2012), pp. 392-407 | DOI | MR | Zbl

[25] Zwick, Dylan Symmetric Kapranov and symmetric tropical ranks (2021) | arXiv | Zbl

Cited by Sources: