Separate continuity of the Lempert function of the spectral ball

We find all matrices $A$ from the spectral unit ball $\Omega_n$ such that the Lempert function $l_{\Omega_n}(A,\cdot)$ is continuous.Comment: small corrections; one reference is adde

Rigid characterizations of pseudoconvex domains

We prove that an open set $D$ in \C^n is pseudoconvex if and only if for any $z\in D$ the largest balanced domain centered at $z$ and contained in $D$ is pseudoconvex, and consider analogues of that characterization in the linearly convex case.Comment: v2: Proposition 14 is improved; v3: Example 15 and the proof of Proposition 14 are change

"Convex" characterization of linearly convex domains

We prove that a $C^{1,1}$-smooth bounded domain $D$ in \C^n is linearly convex if and only if the convex hull of any two discs in $D$ with common center lies in $D.$Comment: to appear in Math. Scand.; v3: Appendix is adde

On the zero set of the Kobayashi--Royden pseudometric of the spectral unit ball

Given $A\in\Omega_n,$ the $n^2$-dimensional spectral unit ball, we show that $B$ is a "generalized" tangent vector at $A$ to an entire curve in $\Omega_n$ if and only if $B$ is in the tangent cone $C_A$ to the isospectral variety at $A.$ In the case of $\Omega_3,$ the zero set of this metric is completely described.Comment: minor changes; to appear in Ann. Polon. Mat

Discontinuity of the Lempert function and the Kobayashi--Royden metric of the spectral ball

Some results on the discontinuity properties of the Lempert function and the Kobayashi pseudometric in the spectral ball are given.Comment: After submitting this paper to a journal in January the authors received a paper by G. Bharali (see arXiv:0704.1966), where some of the problems are similar to that in our pape

New methods in conformal partial wave analysis

We report on progress concerning the partial wave analysis of higher correlation functions in conformal quantum field theory.Comment: 16 page

Financial frictions and the monetary transmission mechanism: theory, evidence and policy implications

This paper provides a brief survey of the role of financial frictions in the monetary transmission mechanism. After noting some of the key stylised facts that any model of the transmission mechanisms must be consistent with, we discuss both the classical interest rate channel and the credit and bank lending channels of monetary transmission. We then review the empirical evidence relating to the relative importance of these channels. Finally we consider what impact the presence of significant financial frictions might have on the conduct of monetary policy JEL Classification: E52, E58, E44bank-lending channel, credit channel, monetary policy, transmission mechanism