Differential Invariants of Conformal and Projective Surfaces [PDF]
, 2007 We show that, for both the conformal and projective groups, all the differential invariants of a generic surface in three-dimensional space can be written as combinations of the invariant derivatives of a single differential invariant. The proof is based
Hubert, Evelyne, Olver, Peter J.
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Multivariable dimension polynomials and new invariants of differential field extensions
International Journal of Mathematics and Mathematical Sciences, Volume 27, Issue 4, Page 201-214, 2001., 2001 We introduce a special type of reduction in the ring of differential polynomials and develop the appropriate technique of characteristic sets that allows to generalize the classical Kolchin′s theorem on differential dimension polynomial and find new differential birational invariants of a finitely generated differential field extension.
Alexander B. Levin
wiley +1 more source
Algebraic and qualitative remarks about the family yy′ = (αxm+k–1 + βxm–k–1)y + γx2m–2k–1
Open Mathematics, 2019 The aim of this paper is the analysis, from algebraic point of view and singularities studies, of the 5-parametric family of differential ...
Rodríguez-Contreras Jorge +2 more
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A Note on Schanuel's Conjectures for Exponential Logarithmic Power Series Fields
, 2012 In [1], J. Ax proved a transcendency theorem for certain differential fields of characteristic zero: the differential counterpart of the still open Schanuel's conjecture about the exponential function over the field of complex numbers [11, page 30].
Kuhlmann, Salma +2 more
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Algorithms yield upper bounds in differential algebra
, 2020 Consider an algorithm computing in a differential field with several commuting derivations such that the only operations it performs with the elements of the field are arithmetic operations, differentiation, and zero testing.
Li, Wei +3 more
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Amitsur's theorem, semicentral idempotents, and additively idempotent semirings
Open MathematicsThe article explores research findings akin to Amitsur’s theorem, asserting that any derivation within a matrix ring can be expressed as the sum of an inner derivation and a hereditary derivation.
Rachev Martin, Trendafilov Ivan
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Nonautonomous Hamiltonian Systems and Morales-Ramis Theory I. The Case $\ddot{x}=f(x,t)$
, 2012 In this paper we present an approach towards the comprehensive analysis of the non-integrability of differential equations in the form $\ddot x=f(x,t)$ which is analogous to Hamiltonian systems with 1+1/2 degree of freedom.
Morales-Ruiz J. J. +3 more
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Castanea sativa mill. flowers as a source of bioactive phenolic compounds [PDF]
, 2014 In the Trás-os-Montes region of Portugal and across a good part of the Mediterranean countries, chestnut trees are a considerable part of the landscape.
Barros, Lillian +5 more
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Remarks on the intrinsic inverse problem
, 2002 The intrinsic differential Galois group is a twisted form of the standard differential Galois group, defined over the base differential field. We exhibit several constraints for the inverse problem of differential Galois theory to have a solution in this
D. Bertrand
semanticscholar +1 more source
Analyses physico-chimiques des eaux de la Lagune Ebrié effectuées de 1979 à 1981 au cours des programmes "Variabilité interannuelle" et "Baie de Biétri" [PDF]
, 1984 Physico-chemical data collections aimed to assess the interannual variability of the lagoon hydroclimate and the impact of an airport dam on the water quality of the Ebrié ...
Chantraine, J.M., Djedje, R., Guiral, D.
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