I explore some consequences of a groundbreaking result of Breimesser and Pearson on the absolutely continuous spectrum of one-dimensional Schrödinger operators. These include an Oracle Theorem that predicts the potential and rather general results on the approach to certain limit potentials. In particular, we prove a Denisov-Rakhmanov type theorem for the general finite gap case. The main theme...

where γj are selfadjoint 4× 4matrices satisfying the relations (2) γjγl + γlγj = 2δl,j . Obviously, if the domain of D0 is defined asH1(R3;C4), then D0 is a selfadjoint operator in L2(R3;C4). The spectrum of D0 is absolutely continuous, it coincides with the complement of the interval (−1, 1) as a set: σ(D0) = σa.c.(D0) = (−∞,−1] ∪ [1,∞). The multiplicity of the spectrum is infinite. We see tha...

We formulate a qualitative argument, based on Heisenberg’s uncertainty principle, to support the claim that when the effects of matter fields are assumed to overshadow the effects of quantum mechanics of spacetime, the discrete spectrum of black hole radiation, as such as predicted by Bekenstein’s proposal for a discrete black hole area spectrum, reduces to Hawking’s black-body spectrum. * e-ma...

BACKGROUND Diabetes mellitus has been historically divided into type 1 and type 2 diabetes, with type 1 being an autoimmune disease and type 2 being primarily a metabolic disease. CONTENT The current diabetes classification scheme needs to be reevaluated because of the accumulating evidence of immune system involvement in the pathophysiology of type 2 diabetes. SUMMARY There are similaritie...

We present a mathematically rigorous proof that the r-mode spectrum of relativistic stars to the rotational lowest order has a continuous part. A rigorous definition of this spectrum is given in terms of the spectrum of a continuous linear operator. This study verifies earlier results by Kojima (1998) about the nature of the r-mode spectrum.