Zobrazeno 1 - 10
of 19
pro vyhledávání: '"Martin Helmer"'
Publikováno v:
Journal of High Energy Physics, Vol 2023, Iss 10, Pp 1-57 (2023)
Abstract We provide evidence through two loops, that rational letters of polylogarithmic Feynman integrals are captured by the Landau equations, when the latter are recast as a polynomial of the kinematic variables of the integral, known as the princ
Externí odkaz:
https://doaj.org/article/00435fd25f064bb384e77c88b42a8ee0
Publikováno v:
Computational Methods and Function Theory. 21:473-504
We study questions of existence and uniqueness of quadrature domains using computational tools from real algebraic geometry. These problems are transformed into questions about the number of solutions to an associated real semi-algebraic system, whic
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::346c351ada4d6b4945b43806ee88353b
https://doi.org/10.1007/s40315-021-00373-w
https://doi.org/10.1007/s40315-021-00373-w
Autor:
Martin Helmer, Michael F. Adamer
Publikováno v:
Journal of Mathematical Chemistry. 58:2061-2093
We study families of chemical reaction networks whose positive steady states are toric, and therefore can be parameterized by monomials. Families are constructed algorithmically from a core network; we show that if a family member is multistationary,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3f1eb012190ccdbd0cf7141c71999c4d
https://doi.org/10.1007/s10910-020-01162-x
https://doi.org/10.1007/s10910-020-01162-x
Autor:
Jonathan D. Hauenstein, Martin Helmer
Publikováno v:
Experimental Mathematics. 31:975-987
Alt's problem, formulated in 1923, is to count the number of four-bar linkages whose coupler curve interpolates nine general points in the plane. This problem can be phrased as counting the number of solutions to a system of polynomial equations whic
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a454afdf1a61183fd032f9bf338a6bc4
https://doi.org/10.1080/10586458.2020.1740835
https://doi.org/10.1080/10586458.2020.1740835
Autor:
Vidit Nanda, Martin Helmer
We describe a new algorithm for computing Whitney stratifications of complex projective varieties. The main ingredients are (a) an algebraic criterion, due to L\^e and Teissier, which reformulates Whitney regularity in terms of conormal spaces and ma
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d6bda1d78eb0fad3da709d1bcb9458a2
http://arxiv.org/abs/2106.14555
http://arxiv.org/abs/2106.14555
Autor:
Elisenda Feliu, Martin Helmer
Publikováno v:
Feliu, E & Helmer, M 2019, ' Multistationarity and Bistability for Fewnomial Chemical Reaction Networks ', Bulletin of Mathematical Biology, vol. 81, no. 4, pp. 1089-1121 . https://doi.org/10.1007/s11538-018-00555-z
Bistability and multistationarity are properties of reaction networks linked to switch-like responses and connected to cell memory and cell decision making. Determining whether and when a network exhibits bistability is a hard and open mathematical p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::be53434d792794c5bce65a9817a6a3bb
https://doi.org/10.1007/s11538-018-00555-z
https://doi.org/10.1007/s11538-018-00555-z
Publikováno v:
Helmer, M & Nødland, B I U 2019, ' Polar degrees and closest points in codimension two ', Journal of Algebra and its Applications, vol. 18, no. 5, 1950095 . https://doi.org/10.1142/S0219498819500956
Suppose that $X_A\subset \mathbb{P}^{n-1}$ is a toric variety of codimension two defined by an $(n-2)\times n$ integer matrix $A$, and let $B$ be a Gale dual of $A$. In this paper we compute the Euclidean distance degree and polar degrees of $X_A$ (a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f2a1a771723390c1473e5e63014ffc1d
https://curis.ku.dk/portal/da/publications/polar-degrees-and-closest-points-in-codimension-two(1d6dd949-45ed-4fb2-b946-aeef7bb83182).html
https://curis.ku.dk/portal/da/publications/polar-degrees-and-closest-points-in-codimension-two(1d6dd949-45ed-4fb2-b946-aeef7bb83182).html
Autor:
Martin Helmer, Corey Harris
Publikováno v:
Harris, C & Helmer, M 2020, ' Segre class computation and practical applications ', Mathematics of Computation, vol. 89, no. 321, pp. 465-491 . https://doi.org/10.1090/mcom/3448
Let $X \subset Y$ be closed (possibly singular) subschemes of a smooth projective toric variety $T$. We show how to compute the Segre class $s(X,Y)$ as a class in the Chow group of $T$. Building on this, we give effective methods to compute intersect
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::68e25537ac2524af54229ef9fbaa1778
http://arxiv.org/abs/1806.07408
http://arxiv.org/abs/1806.07408
Autor:
Martin Helmer, Michael F. Adamer
In this paper we investigate the complexity of model selection and model testing for dynamical systems with toric steady states. Such systems frequently arise in the study of chemical reaction networks. We do this by formulating these tasks as a cons
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1d1e632c100ceb55348baad031f5d678
http://arxiv.org/abs/1707.07650
http://arxiv.org/abs/1707.07650
Autor:
Nathan Bliss, Jose Israel Rodriguez, Courtney R. Gibbons, Martin Helmer, Serkan Hosten, Daniel Smolkin, Carlos Améndola, Isaac Burke, Evan D. Nash
We study the maximum likelihood degree (ML degree) of toric varieties, known as discrete exponential models in statistics. By introducing scaling coefficients to the monomial parameterization of the toric variety, one can change the ML degree. We sho
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::58654a1a89b9127021cd077bbd65247a
http://arxiv.org/abs/1703.02251
http://arxiv.org/abs/1703.02251