OPTIMIZATION OF THE HOT-ELECTRON BOLOMETER AND A CASCADE QUASIPARTICLE AMPLIFIER FOR SPACE ASTRONOMY

Ultra low noise bolometers are required for space - based astronomical observations. Extremely sensitive detectors are necessary for a deep full-sky survey of distant extragalactic sources in the submillimeter-wave region corresponding to the extraterrestrial background spectrum minimum. A deep full-sky survey is the main goal of the Submillimetron project of the cryogenically cooled telescope on the International Space Station [1,2], project CIRCE (NASA) and other projects. Detection of faint sources involvves wide-band continuum observation using direct detectors (bolometers) that are not restricted by the quantum noise of indirect heterodyne receivers. Theoretical estimations and preliminary experiments show that it is possible to realize the necessary sensitivity of 10-18 - 10-19 W/Hz1/2 with a novel concept of the antenna-coupled microbolometers at temperatures 0.1 K. Additional advantages of such detectors are the possibility to operate with a wide range of background load, easy integration in arrays, and direct possibility of polarization measurements

Network Geometry and Complexity

(28 pages, 11 figures)Higher order networks are able to characterize data as different as functional brain networks, protein interaction networks and social networks beyond the framework of pairwise interactions. Most notably higher order networks include simplicial complexes formed not only by nodes and links but also by triangles, tetrahedra, etc. More in general, higher-order networks can be cell-complexes formed by gluing convex polytopes along their faces. Interestingly, higher order networks have a natural geometric interpretation and therefore constitute a natural way to explore the discrete network geometry of complex networks. Here we investigate the rich interplay between emergent network geometry of higher order networks and their complexity in the framework of a non-equilibrium model called Network Geometry with Flavor. This model, originally proposed for capturing the evolution of simplicial complexes, is here extended to cell-complexes formed by subsequently gluing different copies of an arbitrary regular polytope. We reveal the interplay between complexity and geometry of the higher order networks generated by the model by studying the emergent community structure and the degree distribution as a function of the regular polytope forming its building blocks. Additionally, we discuss the underlying hyperbolic nature of the emergent geometry and we relate the spectral dimension of the higher-order network to the dimension and nature of its building blocks

FCC Physics Opportunities: Future Circular Collider Conceptual Design Report Volume 1

We review the physics opportunities of the Future Circular Collider, covering its e+e-, pp, ep and heavy ion programmes. We describe the measurement capabilities of each FCC component, addressing the study of electroweak, Higgs and strong interactions, the top quark and flavour, as well as phenomena beyond the Standard Model. We highlight the synergy and complementarity of the different colliders, which will contribute to a uniquely coherent and ambitious research programme, providing an unmatchable combination of precision and sensitivity to new physics

A topological application of the isoperimetric inequality

Many infinite dimensional topological spaces come with natural uniform structure, often associated to a metric. As an example one can take the Hilbert space H', the sphere S5 C H' or the Grassmann manifold Gk(Ho). We show in this paper that passing from the category of continuous maps to the category of uniformly continuous maps has a non-trivial effect on the homotopy theory. In particular we exhibit some natural fibrations which have continuous sections but have no uniformly continuous (in particular Lipschitz) sections. 1. The Levy measure. For a set A in a metric space X we denote by N(A ), e ? 0, its e-neighborhood. Consider a family {Xi, Ai}, i = 1, 2, ..., of metric spaces Xi with normalized (i.e. Ai(Xi) = 1) Borel measures Ai. We call such a family Levy if for any sequence of Borel sets Ai C Xi, i = 1, 2, . . ., such that lim infi ,0 Ai(Aj) > 0, and for every e > 0 we have limi<,. Mi(Nj(Ai)) = 1. 1.1. Principal Example. Let Xi be isometric to the Euclidean sphere Si C R '+ of radius ri. Take for ,ui the normalized i-dimensional volume element on S'. The family {Xi, Ai } is Levy iff rii-F12 -i,o 0 (see [6]). Proof. Let A C Si be an arbitrary Borel set and let B C Si be a ball (relative to the Riemannian metric in Si) such that /i(B) = ,ui(A). According to the isoperimetric inequality (see [12], [4]) one has Mi(NE(B)) < Ai(NE(A)), e > 0, and the general problem is reduced to the case when Ai are balls. A straight-forward calculation (see for instance, [6], [8]) yields now our assertio

Species diversification – which species should we use?

Large detector systems for particle and astroparticle physics; Particle tracking detectors; Gaseous detectors; Calorimeters; Cherenkov detectors; Particle identification methods; Photon detectors for UV. visible and IR photons; Detector alignment and calibration methods; Detector cooling and thermo-stabilization; Detector design and construction technologies and materials. The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN (Geneva). The initial configuration and expected performance of the detector and associated systems. as established by test beam measurements and simulation studies. is described. © 2008 IOP Publishing Ltd and SISSA