7,064 research outputs found
Families of p-divisible groups with constant Newton polygon
A p-divisible group over a base scheme in characteristic p in general does
not admit a slope filtration. Let X be a p-divisible group with constant Newton
polygon over a normal noetherian scheme S; we prove that there exists an
isogeny from X to Y such that Y admits a slope filtration. In case S is regular
this was proved by N. Katz for dim(S) = 1 and by T. Zink for dim(S) > 0. We
give an example of a p-divisible group over a non-normal base which does not
admit an isogeny to a p-divisible group with a slope filtration.Comment: To be published in Documenta Mathematic
Moduli of abelian varieties and p-divisible groups
Lecture notes at a conference on Arithmetic Geometry, Goettingen, July/August
2006: Density of ordinary Hecke orbits and a conjecture by Grothendieck on
deformations of p-divisible groups.Comment: 92 page
Velocity control of a 2D dynamic walking robot
In this abstract we introduce velocity control for our 2D dynamic walking robot Dribbel [1] (figure 1) and show that, by âclosing the loopâ, this automatically leads to increased robustness
Geometric dynamics analysis of humanoids - locked inertia
The advantage of geometric dynamics analysis over most classical 3D analysis is that the equations are coordinate- neutral: as long as all quantities are expressed in the same coordinate frame, the equations are correct
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