We survey algorithms for computing isogenies between elliptic curves defined over a field of characteristic either 0 or a large prime. We introduce a new algorithm that computes an isogeny of degree ` (` different from the characteristic) in time quasi-linear with respect to `. This is based in particular on fast algorithms for power series expansion of the Weierstrass ℘-function and related fu...

As a follow-up to a recent paper considering two symmetric queues, the Shortest Queue First service discipline is presently analysed for two general asymmetric queues. Using the results previously established and assuming exponentially distributed service times, the bivariate Laplace transform of workloads in each queue is shown to depend on the solution M to a two-dimensional functional equati...

Let T be a consistent o-minimal theory extending the theory of densely ordered groups and let T ′ be a consistent theory. Then there is a complete theory T ∗ extending T such that T is an open core of T ∗, but every model of T ∗ interprets a model of T ′. If T ′ is NIP, T ∗ can be chosen to be NIP as well. From this we deduce the existence of an NIP expansion of the real field that has no dista...

The classical action of a two dimensional N = 2 supersymmetric theory, characterized by a general Kähler potential, is written down on a non(anti)commutative superspace. The action has a power series expansion in terms of the determinant of the non(anti)commutativity parameter C αβ. The theory is explicitly shown to preserve half of the N = 2 supersymmetry, to all orders in (det C) n. The resul...

The pixel-to-pixel flat field changes noted by Bohlin and Mack (2005) for the WFC are further quantified. During each period between anneals, a population of pixels with lowered sensitivity develops which is largely reset by the next anneal. The sensitivity deficits are twice as large in the blue as in the red. The pixels with lowered sensitivity appear to be a unique set each anneal cycle, rat...

In our entry to the new HARD track, we have investigated two methods of interactively refining user search formulations. One method consists of asking the user to select a number of sentences that may represent relevant documents, and then using the documents, whose sentences were selected for query expansion. The second method is to show to the user a list of noun phrases, extracted from the i...

In this paper, we obtain new observability inequalities for the vibrating string. This work was motivated by a recent paper of Szijártó and Hegedűs in which the authors ask the question of determining the initial data by only knowing the position of the string at two distinct time instants. The choice of the observation instants is crucial and the estimations rely on the Fourier series expansio...

We show how to find series expansions for π of the form π = ∞ n=0 S(n) mn pn a n , where S(n) is some polynomial in n (depending on m, p, a). We prove that there exist such expansions for m = 8k, p = 4k, a = (−4) k , for any k, and give explicit examples for such expansions for small values of m, p and a.