Search

We use inverse scattering methods, generalized for a specific class of complex potentials, to construct a one parameter family of complex potentials V(s, r) which have the property that the zero energy s-wave Jost function, as a function of s alone, is identical to Riemann's $\xi$ function whose zeros are the non-trivial zeros of the zeta function. These potentials have an asymptotic expansion in inverse powers of s(s-1) with real coefficients V_n(r) which are explicitly calculated. We show that the validity of the Riemann hypothesis depends essentially on simple integrability properties of the first order coefficient, V_1(r). In the case studied in this paper, this coefficient does not satisfy these conditions, but proof of that fact does indicate several possibilities for proceeding further., Comment: 107 pages, 1 figure, Latex

We show that, even for a soft collision like forward elastic scattering, the phase of the amplitude is extremely sensitive to a breakdown of strict causality in local QFT. This is especially the case when the breakdown is manifested by a failure of polynomial boundedness which leads to amplitudes that in some complex direction have order 1 exponential growth in $|\sqrt{s}|$., 8 pages, including one postscript figure, latex with epsf.sty

In this paper we consider non-relativistic quantum mechanics on a space with an additional internal compact dimension, i.e. $R^3\otimes S^1$ instead of $R^3$. More specifically we study potential scattering for this case and the analyticity properties of the forward scattering amplitude, $T_{nn}(K)$, where $K^2$ is the total energy and the integer n denotes the internal excitation of the incoming particle. The surprising result is that the analyticity properties which are true in $R^3$ do not hold in $R^3\otimes S^1$. For example, $T_{nn}(K)$, is \underline{not} analytic in K for $ImK>0$, for n such that $(|n|/R)>\mu$, where R is the radius of $S^1$, and $\mu^{-1}$ is the exponential range of the potential, $V(r,\phi)=O(e^{-\mu r})$ for large r. We show by explicit counterexample that $T_{nn}(K)$ for $n\neq0$, can have singularities on the physical energy sheet. We also discuss the motivation for our work, and briefly the lesson it teaches us., Comment: LaTeX file, 23 pages, RU94-6-B