The quasi-algebraic ring of~conditions of~$\mathbb C^n$
Izvestiya. Mathematics , Tome 86 (2022) no. 1, pp. 169-202.

Voir la notice de l'article provenant de la source Math-Net.Ru

An exponential sum is a linear combination of characters of the additive group of $\mathbb C^n$. We regard $\mathbb{C}^n$ as an analogue of the torus $(\mathbb{C}\setminus0)^n$, exponential sums as analogues of Laurent polynomials, and exponential analytic sets ($\mathrm{EA}$-sets), that is, the sets of common zeros of finite systems of exponential sums, as analogues of algebraic subvarieties of the torus. Using these analogies, we define the intersection number of $\mathrm{EA}$-sets and apply the De Concini–Procesi algorithm to construct the ring of conditions of the corresponding intersection theory. To construct the intersection number and the ring of conditions, we associate an algebraic subvariety of a multidimensional complex torus with every $\mathrm{EA}$-set and use the methods of tropical geometry. By computing the intersection number of the divisors of arbitrary exponential sums $f_1,\dots,f_n$, we arrive at a formula for the density of the $\mathrm{EA}$-set of common zeros of the perturbed system $f_i(z+w_i)$, where the perturbation $\{w_1,\dots,w_n\}$ belongs to a set of relatively full measure in $\mathbb{C}^{n\times n}$. This formula is analogous to the formula for the number of common zeros of Laurent polynomials.
Keywords: exponential sum, intersection number, Newton polytope, tropical geometry.
@article{IM2_2022_86_1_a5,
     author = {B. Ya. Kazarnovskii},
     title = {The quasi-algebraic ring of~conditions of~$\mathbb C^n$},
     journal = {Izvestiya. Mathematics },
     pages = {169--202},
     publisher = {mathdoc},
     volume = {86},
     number = {1},
     year = {2022},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2022_86_1_a5/}
}
TY  - JOUR
AU  - B. Ya. Kazarnovskii
TI  - The quasi-algebraic ring of~conditions of~$\mathbb C^n$
JO  - Izvestiya. Mathematics 
PY  - 2022
SP  - 169
EP  - 202
VL  - 86
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_2022_86_1_a5/
LA  - en
ID  - IM2_2022_86_1_a5
ER  - 
%0 Journal Article
%A B. Ya. Kazarnovskii
%T The quasi-algebraic ring of~conditions of~$\mathbb C^n$
%J Izvestiya. Mathematics 
%D 2022
%P 169-202
%V 86
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_2022_86_1_a5/
%G en
%F IM2_2022_86_1_a5
B. Ya. Kazarnovskii. The quasi-algebraic ring of~conditions of~$\mathbb C^n$. Izvestiya. Mathematics , Tome 86 (2022) no. 1, pp. 169-202. http://geodesic.mathdoc.fr/item/IM2_2022_86_1_a5/

[1] C. De Concini, C. Procesi, “Complete symmetric varieties. II. Intersection theory”, Algebraic groups and related topics (Kyoto/Nagoya, 1983), Adv. Stud. Pure Math., 6, North-Holland, Amsterdam, 1985, 481–513 | DOI | MR | Zbl

[2] C. De Concini, “Equivariant embeddings of homogeneous spaces”, Proceedings of the international congress of mathematicians (Berkeley, Calif., 1986), v. 1, Amer. Math. Soc., Providence, RI, 1987, 369–377 | MR | Zbl

[3] B. Ya. Kazarnovskii, A. G. Khovanskii, A. I. Esterov, “Newton polytopes and tropical geometry”, Russian Math. Surveys, 76:1 (2021), 91–175 | DOI | DOI | MR | Zbl

[4] B. Ya. Kazarnovskii, “Action of the complex Monge–Ampère operator on piecewise-linear functions and exponential tropical varieties”, Izv. Math., 78:5 (2014), 902–921 | DOI | DOI | MR | Zbl

[5] B. Ya. Kazarnovskii, “On the action of the complex Monge–Ampère operator on piecewise linear functions”, Funct. Anal. Appl., 48:1 (2014), 15–23 | DOI | DOI | MR | Zbl

[6] I. Itenberg, G. Mikhalkin, E. Shustin, Tropical algebraic geometry, Oberwolfach Semin., 35, 2nd ed., Birkhäuser Verlag, Basel, 2009, x+104 pp. | DOI | MR | Zbl

[7] D. Maclagan, B. Sturmfels, Introduction to tropical geometry, Grad. Stud. Math., 161, Amer. Math. Soc., Providence, RI, 2015, xii+363 pp. | DOI | MR | Zbl

[8] B. Ya. Kazarnovskii, “c-fans and Newton polyhedra of algebraic varieties”, Izv. Math., 67:3 (2003), 439–460 | DOI | DOI | MR | Zbl

[9] B. Ya. Kazarnovskii, “Exponential analytic sets”, Funct. Anal. Appl., 31:2 (1997), 86–94 | DOI | DOI | MR | Zbl

[10] A. G. Khovanskii, Fewnomials, Transl. Math. Monogr., 88, Amer. Math. Soc., Providence, RI, 1991, viii+139 pp. | DOI | MR | MR | Zbl

[11] B. Ya. Kazarnovskij, “On the zeros of exponential sums”, Soviet Math. Dokl., 23 (1981), 347–351 | MR | Zbl

[12] B. Ya. Kazarnovskii, “Newton polyhedra and zeros of systems of exponential sums”, Funct. Anal. Appl., 18:4 (1984), 299–307 | DOI | MR | Zbl

[13] D. N. Bernstein, “The number of roots of a system of equations”, Funct. Anal. Appl., 9:3 (1975), 183–185 | DOI | MR | Zbl

[14] H. Weyl, “Mean motion”, Amer. J. Math., 60:4 (1938), 889–896 | DOI | MR | Zbl

[15] B. Zilber, “Exponential sums equations and the Schanuel conjecture”, J. London Math. Soc. (2), 65:1 (2002), 27–44 | DOI | MR | Zbl

[16] E. Bombieri, D. Masser, U. Zannier, “Anomalous subvarieties – structure theorems and applications”, Int. Math. Res. Not. IMRN, 2007:19 (2007), rnm057, 33 pp. | DOI | MR | Zbl

[17] M. Brion, “The structure of polytope algebra”, Tohoku Math. J. (2), 49:1 (1997), 1–32 | DOI | MR | Zbl

[18] A. Esterov, “Tropical varieties with polynomial weights and corner loci of piecewise polynomials”, Mosc. Math. J., 12:1 (2012), 55–76 ; arXiv: 1012.5800 | MR | Zbl

[19] E. Katz, “A tropical toolkit”, Expo. Math., 27:1 (2009), 1–36 | DOI | MR | Zbl

[20] L. Allerman, J. Rau, “First steps in tropical intersection theory”, Math. Z., 264:3 (2010), 633–670 | DOI | MR | Zbl

[21] L. Allermann, “Tropical intersection products on smooth varieties”, J. Eur. Math. Soc. (JEMS), 14:1 (2012), 107–126 | DOI | MR | Zbl

[22] G. M. Bergman, “The logarithmic limit-set of an algebraic variety”, Trans. Amer. Math. Soc., 157 (1971), 459–469 | DOI | MR | Zbl