We consider the following general hidden hubs model: an n × n random matrix A with a subset S of k special rows (hubs): entries in rows outside S are generated from the (Gaussian) probability distribution p0 ∼ N(0, σ 0); for each row in S, some k of its entries are generated from p1 ∼ N(0, σ 1), σ1 > σ0, and the rest of the entries from p0. The special rows with higher variance entries can be v...

It is proposed to shoot a molecule through a pipe of mesoscopic scale. The molecule should effectifely carry two spins and antiferromagnetic chains should be embedded in the wall of the tube. If the momentum is detected before and behind the tube, a projection of the molecular spins ~σ1 and ~σ2 takes place. If the molecule did not loose momentum inside the tube, it has a vanishing squared total...

The importance of structure coefficients and analogs of regression weights for analysis within the general linear model (GLM) has been well-documented. The purpose of this study was to investigate bias in squared structure coefficients in the context of multiple regression and to determine if a formula that had been shown to correct for bias in squared Pearson correlation coefficients and coeff...

Despite its many strengths, the SAINTS (Squared-Autoregressive-Independent-Variable Nominal Term Structure) model of Constantinides (1992) cannot be directly compared with other popular term structure models such as Vasicek (1977) and Cox, Ingersoll and Ross (1985) mainly because the stochastic discount factor of the model is exogenously spec-iied. The primary motivation of this paper is to nd ...

Consider a normal model with unknown mean bounded by a known constant. This paper deals with minimax estimation of the squared mean. We establish an expression for the asymptotic minimax risk. This result is applied in nonparametric estimation of quadratic functionals.

Our main, novel, result is that a certain non-central chi-squared mixture of distributions itself scaled distribution. From this and link to known on representation for central distribution, numerous further results, both old new, ensue. These include results F, F Libby–Novick distributions. The main involves all with the same degrees freedom; it also extended case where mixing distribution has...