We introduce tests for finite-sample linear regressions with heteroskedastic errors. The tests are exact, i.e., they have guaranteed type I error probabilities when bounds are known on the range of the dependent variable, without any assumptions about the noise structure. We provide upper bounds on probability of type II errors, and apply the tests to empirical data.

It is the object of this paper to study the existence and the form of minimal projections in some spaces of tensor products of Banach spaces. We answer a question of Franchetti and Cheney for finitely codimensional subspaces in C(K ) [1].

OBJECTIVES To assess prospectively the effects of perceived non-reciprocity of exchange in three different types of social engagement on health functioning in early old age. METHODS In the frame of the prospective French GAZEL cohort study, data on reciprocity in three types of role-related social engagement (principal regular activity in everyday life, marital role relationship, trusting rel...

In this paper we are concerned with labelled apparent contours, namely with apparent contours of generic orthogonal projections of embedded surfaces in R, endowed with a suitable depth information. We show that there exists a finite set of elementary moves (i.e. local topological changes) on labelled apparent contours such that the following theorem holds: two generic embeddings of a closed sur...

We study the L2 → L∞ norms of spectral projections and spectral multipliers of left-invariant elliptic and subelliptic second-order differential operators on homogeneous Lie groups. We obtain a precise description of the L2 → L∞ norms of spectral multipliers for some class of operators which we call quasi-homogeneous. As an application we prove a stronger version of Alexopoulos’ spectral multip...

We consider a 2 d.o.f. Hamiltonian system with one degree of freedom corresponding to fast motion and the other corresponding to slow motion. The ratio of the time derivatives of slow and fast variables is of order 0 < ε ≪ 1. At frozen values of the slow variables there is a separatrix on the phase plane of the fast variables and there is a region in the phase space (the domain of separatrix cr...

We propose to realize Weyl semimetals in a cubic optical lattice. We find that there exist three distinct Weyl semimetal phases in the cubic optical lattice for different parameter ranges. One of them has two pairs of Weyl points and the other two have one pair of Weyl points in the Brillouin zone. For a slab geometry with (010) surfaces, the Fermi arcs connecting the projections of Weyl points...

Our survey of private manufacturing firms finds the size of hidden ‘unofficial’ activity to be much larger in Russia and Ukraine than in Poland, Slovakia and Romania. A comparison of cross-country averages shows that managers in Russia and Ukraine face higher effective tax rates, worse bureaucratic corruption, greater incidence of mafia protection, and have less faith in the court system. Our f...

We show that the addition of name induction to the theory EETJ + (LEM-IN) of explicit elementary types with join yields a theory proof-theoretically equivalent to ID1.