Period functions for Maass cusp forms for Γ0(p)\Gamma_0(p): a transfer operator approach

We characterize the Maass cusp forms for Hecke congruence subgroups of prime level as 1-eigenfunctions of a finite-term transfer operator.Comment: 17 pages, 6 figure

Amount of failure of upper-semicontinuity of entropy in noncompact rank one situations, and Hausdorff dimension

Recently, Einsiedler and the authors provided a bound in terms of escape of mass for the amount by which upper-semicontinuity for metric entropy fails for diagonal flows on homogeneous spaces $\Gamma\backslash G$, where $G$ is any connected semisimple Lie group of real rank 1 with finite center and $\Gamma$ is any nonuniform lattice in $G$. We show that this bound is sharp and apply the methods used to establish bounds for the Hausdorff dimension of the set of points which diverge on average.Comment: 24 page

Dynamical Crystallization in the Dipole Blockade of Ultracold Atoms

We describe a method for controlling many-body states in extended ensembles of Rydberg atoms, forming crystalline structures during laser excitation of a frozen atomic gas. Specifically, we predict the existence of an excitation number staircase in laser excitation of atomic ensembles into Rydberg states. Each step corresponds to a crystalline state with a well-defined of regularly spaced Rydberg atoms. We show that such states can be selectively excited by chirped laser pulses. Finally, we demonstarte that, sing quantum state transfer from atoms to light, such crystals can be used to create crystalline photonic states and can be probed via photon correlation measurements

Cedric Price’s Pop-Up Parliament: A Role Model for Media Architecture and Data Politics

The digital era has supposedly had a drastic impact on contemporary forms of political debate. Live-tweets, podcasts, and posts have become the main channels for politics, polemics, and populism alike. But these tendencies are not only an acceleration of the politics of media brought about by the logics behind television, cybernetics, and computation in the post-war era. They gained strength when populist politics appropriated information access via mass media, which once promised the emancipation of ordinary citizens by architectural means through pop-culture. In this essay I seek to elaborate how Cedric Price’s 1965 design of the Pop-Up Parliament dealt with a media-technical condition of politics, while proposing that architecture was an integral part of the media network of governing. Price’s project is paradigmatic of the 1960s, a period when the media operations of information compression, prediction, and audience targeting became more decisive for politics than the content of debate. This analysis allows us, on the one hand, to problematise conventional definitions of populism towards a media-based concept, and on the other, to further our understanding of architecture as a political medium operating directly with media such as documents, television, and computers. This essay argues that the advent of digital media calls for a different architectural history of populism, one which engages with the operativity of media and cultural techniques, rather than relying upon the symbolic representation of ideology in architecture