There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

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The Observation of Gravitational Waves from a Binary Black Hole Merger

From the Publisher: 
The accessible presentation of this book gives both a general view of the entire computer vision enterprise and also offers sufficient detail to be able to build useful applications. Users learn techniques that have proven to be useful by first-hand experience and a wide range of mathematical methods. A CD-ROM with every copy of the text contains source code for programming practice, color images, and illustrative movies. Comprehensive and up-to-date, this book includes essential topics that either reflect practical significance or are of theoretical importance. Topics are discussed in substantial and increasing depth. Application surveys describe numerous important application areas such as image based rendering and digital libraries. Many important algorithms broken down and illustrated in pseudo code. Appropriate for use by engineers as a comprehensive reference to the computer vision enterprise.

Computer vision : a modern approach = 计算机视觉 : 一种现代的方法

Researchers demonstrate the ability to multiplex and transfer data between twisted beams of light with different amounts of orbital angular momentum — a development that provides new opportunities for increasing the data capacity of free-space optical communications links.

/pdf/terabit-free-space-data-transmission-employing-orbital-47zsgn5cdx.pdf

Terabit free-space data transmission employing orbital angular momentum multiplexing

We demonstrate a single-photon SWAP gate between polarization and spatial-momentum qubits on a silicon-on-oxide chip. Phase coherence of the SWAP gate operation is confirmed via single-photon self-interference, with visibility up to 98.89%.

A Phase-Coherent On-Chip Single-Photon SWAP Gate

We demonstrate a pulsed entanglement source whose flux is sufficiently high that it leads to reduced quantum-interference visibility due to multiple-pair emissions. An array of such pulsed downconverters can be configured to yield single photons on demand.

High-Flux Pulsed Polarization-Entangled Photon Source for Generating Single Photons on Demand

We experimentally demonstrate a chip-scale polarization to spatial-momentum qubit SWAP gate. High fidelity of the SWAP gate operation is confirmed by quantum state tomography, with average gate fidelity up to 97.30%.

Quantum State Tomography of an On-chip Polarization-Spatial Qubit SWAP Gate

Academic and Research Staff

Recent work has highlighted the potential applications of two-photon coherent states (TCS), also known as squeezed states, in optical communications and precision measurements. These states have non-classical noise statistics. Their predicted generation schemes include the degenerate parametric amplifier, degenerate four-wave mixing (DFWM), and multi-photon optical bistability. The preceding generation schemes have been analyzed to varying degrees of approximation, but no experimental observation of TCS has been reported as yet. In this paper we describe an experiment measuring the quantum statistics of light that has undergone DFWM to look for squeezed-state generation via this process.

Jeffrey H. Shapiro

Papers

A Phase-Coherent On-Chip Single-Photon SWAP Gate

High-Flux Pulsed Polarization-Entangled Photon Source for Generating Single Photons on Demand

Quantum State Tomography of an On-chip Polarization-Spatial Qubit SWAP Gate

Academic and Research Staff

Quantum Noise Measurements in Degenerate Four-Wave Mixing