Abstract
Let G be a simple graph on the vertex set \({\{1,\ldots,n\}}\) with m edges. An algebraic object attached to G is the ideal P G generated by diagonal 2-minors of an \({n \times n}\) matrix of variables. We prove that if G is bipartite, then every initial ideal of P G is generated by squarefree monomials of degree at most \({\lfloor{\frac{m+n+1}{2}} \rfloor}\). Furthermore, we completely characterize all connected graphs G for which P G is the toric ideal associated to a finite simple graph. Finally we compute in certain cases the universal Gröbner basis of P G .
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I. Bermejo, I. Garcia-Marco and E. Reyes, Graphs and complete intersection toric ideals, J. Algebra Appl., 14 (2015), 1540011, pp 37.
Bogart T., Hemmecke R., Petrovic S.: Universal Gröbner bases of colored partition identities. Exp. Math., 21, 395–401 (2012)
J. A. De Loera, Triangulations of Polytopes and Computational Algebra, PhD thesis, Cornell University (1995).
P. Diaconis, D. Eisenbud and B. Sturmfels, Lattice walks and primary decomposition, in: B. E. Sagan, R. P. Stanley (Eds.), Mathematical Essays in Honor of Gian-Carlo Rota, Birkhäuser (Boston, 1998), pp. 173–193.
Ene V., Qureshi A.A.: Ideals generated by diagonal 2-minors. Comm. Algebra, 41, 3058–3066 (2013)
Morton J.: Relations among conditional probabilities. J. Symbolic Comput., 50, 478–492 (2013)
Ohsugi H., Hibi T.: Toric ideals generated by quadratic binomials. J. Algebra 218, 509–527 (1999)
Ohsugi H., Hibi T.: Toric ideals of finite graphs and adjacent 2-minors. Math. Scand., 114, 185–190 (2014)
Rapallo F.: Algebraic Markov bases and MCMC for two-way contingency tables. Scand. J. Statist., 30, 385–397 (2003)
A. Schrijver, Theory of Linear and Integer Programming, John Wiley and Sons (New York, 1986).
B. Sturmfels, Gröbner Bases and Convex Polytopes, University Lecture Series, No. 8, American Mathematical Society (Providence, R.I., 1995).
Tatakis C., Thoma A.: On the universal Gröbner bases of toric ideals of graphs. J. Combin. Theory Ser. A, 118, 1540–1548 (2011)
R. H. Villarreal, Monomial Algebras, Marcel Dekker (New York, 2001).
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This work was carried out during the tenure of an ERCIM “Alain Bensoussan” Fellowship Programme. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 246016.
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Katsabekis, A. Toric ideals and diagonal 2-minors. Acta Math. Hungar. 150, 83–98 (2016). https://doi.org/10.1007/s10474-016-0651-9
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DOI: https://doi.org/10.1007/s10474-016-0651-9