The exponent of a variety of algebras over a field of characteristic zero has been recently proved to be an integer. Through this scale we can now classify all minimal varieties of a given exponent and of finite basic rank. As a consequence we describe the corresponding T-ideals of the free algebra, and we compute the asymptotics of the related codimension sequences. We then verify in this sett...

– We classify pointed finite-dimensional complex Hopf algebras whose group of group-like elements is abelian of prime exponent p, p > 17. The Hopf algebras we find are members of a general family of pointed Hopf algebras we construct from Dynkin diagrams. As special cases of our construction we obtain all the Frobenius–Lusztig kernels of semisimple Lie algebras and their parabolic subalgebras. ...

We point out that local minimizing curves, or troughs, of the smallest finite-time Lyapunov exponent (FTLE) field computed over a time interval [t(0), t] and graphed over trajectory positions at time t mark attracting Lagrangian coherent structures (LCSs) at t. For two-dimensional area-preserving flows, we conclude that computing the largest forward-time FTLE field by itself is sufficient for l...

The Finite-time Lyapunov Exponent (FTLE) is a measure for the rate of separation of particles in time-dependent flow fields. It provides a valuable tool for the analysis of unsteady flows. Commonly it is defined based on the flow map, analyzing the separation of trajectories of nearby particles over a finite-time span. This paper proposes a localized definition of the FTLE using the Jacobian ma...

We propose efficient Eulerian methods for approximating the finite-time Lyapunov exponent (FTLE). The idea is to compute the related flow map using the Level Set Method and the Liouville equation. There are several advantages of the proposed approach. Unlike the usual Lagrangian-type computations, the resulting method requires the velocity field defined only at discrete locations. No interpolat...

Fractal surfaces (’patchwork quilts’) are shown to arise under most general circumstances involving simple bitwise operations between real numbers. A theory is presented for all bitwise operations on a finite alphabet which are not governed by chance. It is shown that these models give rise to a roughness exponent H that shapes the resulting spatial patterns, larger values of the exponent leadi...

where Aj(z) (j = 0, 1, . . . , k) are meromorphic functions with finite order. Under some conditions on the coefficients, we show that all meromorphic solutions f 6≡ 0 of the above equations have an infinite order and infinite lower order. Furthermore, we give some estimates of their hyper-order, exponent and hyper-exponent of convergence of distinct zeros. We improve the results due to Kwon; C...

Consider hyperelliptic curves C of fixed genus over a finite field F. Let L be a finite abelian group of exponent dividng N . We give an asymptotic formula in |F|, with explicit error term, for the proportion of C for which Jac(C)[N ](F) ∼= L.

We present a lower bound for the exponent of the group of rational points of an elliptic curve over a finite field. Earlier results considered finite fields Fqm where either q is fixed or m = 1 and q is prime. Here we let both q and m vary and our estimate is explicit and does not depend on the elliptic curve.