Bounded Height in Pencils of Finitely Generated Subgroups

We prove height bounds concerning intersections of finitely generated subgroups in a torus with algebraic subvarieties, all varying in a pencil. This vastly extends the previously treated constant case and involves entirely different, and more delicate, techniques

UNLIKELY INTERSECTIONS FOR CURVES IN MULTIPLICATIVE GROUPS OVER POSITIVE CHARACTERISTIC

The conjectures associated with the names of Zilber-Pink greatly generalize results associated with the names of Manin-Mumford and Mordell-Lang, but unlike the latter they are at present restricted to zero characteristic. We make a start on removing this restriction by stating a conjecture for curves in multiplicative groups over positive characteristic, and we verify the conjecture in three dimensions as well as for some special lines in general dimension. We also give an example where the finite set in question can be explicitly determine

Crew radiation dose from the plume of a high impulse gas-core nuclear rocket during a Mars mission

Crew radiation dose from plume of high impulse gas-core nuclear rocket during Mars missio

Crew radiation dose from a gas-core nuclear rocket plume

Crew radiation dose from gas-core nuclear rocket plum

Mirror reflectometer based on optical cavity decay time

Described is a reflectometer capable of making reflectivity measurements of low-loss highly reflecting mirror coatings and transmission measurements of low-loss antireflection coatings. The technique directly measures the intensity decay time of an optical cavity comprised of low-loss elements. We develop the theoretical framework for the device and discuss in what conditions and to what extent the decay time represents a true measure of mirror reflectivity. Current apparatus provides a decay time resolution of 10 nsec and has demonstrated a cavity total loss resolution of 5 ppm

Vapor-pressure data extrapolated to 1000 atmospheres /1.01 times 108N/m2/ for 13 refractory materials with low thermal absorption cross sections

Predicted high temperature vapor pressure data for refractory materials with low thermal absorption cross section

UNLIKELY INTERSECTIONS FOR CURVES IN MULTIPLICATIVE GROUPS OVER POSITIVE CHARACTERISTIC

The conjectures associated with the names of Zilber-Pink greatly generalize results associated with the names of Manin-Mumford and Mordell-Lang, but unlike the latter they are at present restricted to zero characteristic. We make a start on removing this restriction by stating a conjecture for curves in multiplicative groups over positive characteristic, and we verify the conjecture in three dimensions as well as for some special lines in general dimension. We also give an example where the finite set in question can be explicitly determine

CM relations in fibered powers of elliptic families

Let $E_\lambda$ be the Legendre family of elliptic curves. Given $n$ linearly independent points $P_1,\dots , P_n \in E_\lambda\left(\overline{\mathbb{Q}(\lambda)}\right)$ we prove that there are at most finitely many complex numbers $\lambda_0$ such that $E_{\lambda_0}$ has complex multiplication and $P_1(\lambda_0), \dots ,P_n(\lambda_0)$ are dependent over $End(E_{\lambda_0})$. This implies a positive answer to a question of Bertrand and, combined with a previous work in collaboration with Capuano, proves the Zilber-Pink conjecture for a curve in a fibered power of an elliptic scheme when everything is defined over $\overline{\mathbb{Q}}$.Comment: The formulation of Theorem 2.1 is now correc

Torsion points on families of squares of elliptic curves

In a recent paper we proved that there are at most finitely many complex numbers λ ≠ 0,1 such that the points $${(2,\sqrt{2(2-\lambda)})}$$ and $${(3, \sqrt{6(3-\lambda)})}$$ are both torsion on the elliptic curve defined by Y 2=X(X − 1)(X − λ). Here we give a generalization to any two points with coordinates algebraic over the field Q(λ) and even over C(λ). This implies a special case of a variant of Pink's Conjecture for a variety inside a semiabelian scheme: namely for any curve inside any scheme isogenous to a fibred product of two isogenous elliptic scheme