Reduction of Algebraic Parametric Systems by Rectification of their Affine Expanded Lie Symmetries [PDF]
, 2006 Lie group theory states that knowledge of a $m$-parameters solvable group of symmetries of a system of ordinary differential equations allows to reduce by $m$ the number of equations. We apply this principle by finding some \emph{affine derivations} that
G. Bluman +5 more
core +8 more sources
Automatic Matching of Multi-Source Satellite Images: A Case Study on ZY-1-02C and ETM+
Applied Sciences, 2017 The ever-growing number of applications for satellites is being compromised by their poor direct positioning precision. Existing orthoimages, such as enhanced thematic mapper (ETM+) orthoimages, can provide georeferences or improve the geo-referencing ...
Bo Wang +3 more
doaj +1 more source
Testing Low Complexity Affine-Invariant Properties [PDF]
, 2012 Invariance with respect to linear or affine transformations of the domain is arguably the most common symmetry exhibited by natural algebraic properties.
Bhattacharyya, Arnab +2 more
core +2 more sources
Extended affine Weyl groups and Frobenius manifolds [PDF]
, 1996 We define certain extensions of affine Weyl groups (distinct from these considered by K. Saito [S1] in the theory of extended affine root systems), prove an analogue of Chevalley theorem for their invariants, and construct a Frobenius structure on their ...
Dubrovin, Boris, Zhang, Youjin
core +5 more sources
Functions dividing their Hessian determinants and affine spheres [PDF]
, 2016 The nonzero level sets of a homogeneous, logarithmically homogeneous, or translationally homogeneous function are affine spheres if and only if the Hessian determinant of the function is a multiple of a power or an exponential of the function.
Fox, Daniel J. F.
core +1 more source
A quadratic Poisson Gel'fand-Kirillov problem in prime characteristic [PDF]
, 2015 The quadratic Poisson Gel’fand-Kirillov problem asks whether the field of fractions of a Poisson algebra is Poisson birationally equivalent to a Poisson affine space, i.e. to a polyno-mial algebra K[X1,..., Xn] with Poisson bracket defined by {Xi, Xj} =
Launois, Stephane, Lecoutre, Cesar
core +2 more sources
Diagonal Coinvariants and Double Affine Hecke Algebras [PDF]
, 2003 We establish a q-generalization of Gordon's theorem that the space of diagonal coinvariants has a quotient identified with a perfect representation of the rational double affine Hecke algebra.
Cherednik, Ivan
core +3 more sources
Automated Coregistered Segmentation for Volumetric Analysis of Multiparametric Renal MRI. [PDF]
Magn Reson MedABSTRACT Purpose This study aims to develop and evaluate a fully automated deep learning‐driven postprocessing pipeline for multiparametric renal MRI, enabling accurate kidney alignment, segmentation, and quantitative feature extraction within a single efficient workflow. Methods Our method has three main stages.
Ghoul A +8 more
europepmc +2 more sources
Classical Yang-Baxter Equation and Left Invariant Affine Geometry on Lie Groups
, 2002 Let G be a Lie group with Lie algebra $ \Cal G: = T_\epsilon G$ and $T^*G = \Cal G^* \rtimes G$ its cotangent bundle considered as a Lie group, where G acts on $\Cal G^*$ via the coadjoint action.
Diatta, Andre, Medina, Alberto
core +2 more sources
Automorphism groups of Koras-Russell threefolds of the second kind [PDF]
, 2015 We determine the automorphism groups of Koras-Russell threefolds of the second kind. In particular we show that these groups are semi-direct products of two subgroups, one given by the multiplicative group and the other isomorphic to a polynomial ring in
Petitjean, Charlie
core +2 more sources