Cosmological singularities in FLRW spacetimes

In this talk we review the appearance of new types of singularities (big rip, sudden singularities...) in FLRW cosmological models that have arisen on considering explanations for accelerated expansion of our universe.Comment: 3 pages, ws-procs975x65.cls to appear in Proceedings of 12th Marcel Grossmann Meeting, Pari

Beam-beam-induced orbit effects at LHC

For high bunch intensities the long-range beam-beam interactions are strong enough to provoke effects on the orbit. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are presented in this paper.Comment: 5 pages, contribution to the ICFA Mini-Workshop on Beam-Beam Effects in Hadron Colliders, CERN, Geneva, Switzerland, 18-22 Mar 201

Classifying Ellipsis in Dialogue: A Machine Learning Approach

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Quantum Modelling of Electro-Optic Modulators

Many components that are employed in quantum information and communication systems are well known photonic devices encountered in standard optical fiber communication systems, such as optical beamsplitters, waveguide couplers and junctions, electro-optic modulators and optical fiber links. The use of these photonic devices is becoming increasingly important especially in the context of their possible integration either in a specifically designed system or in an already deployed end-to-end fiber link. Whereas the behavior of these devices is well known under the classical regime, in some cases their operation under quantum conditions is less well understood. This paper reviews the salient features of the quantum scattering theory describing both the operation of the electro-optic phase and amplitude modulators in discrete and continuous-mode formalisms. This subject is timely and of importance in light of the increasing utilization of these devices in a variety of systems, including quantum key distribution and single-photon wavepacket measurement and conformation. In addition, the paper includes a tutorial development of the use of these models in selected but yet important applications, such as single and multi-tone modulation of photons, two-photon interference with phase-modulated light or the description of amplitude modulation as a quantum operation.Comment: 29 pages, 10 figures, Laser and Photonics Reviews (in press

Artificial Contraception is Associated With Increased Numbers of Induced Abortions

Since the sexual revolution, it has been a widely accepted fact that contraceptives have been a necessity for our society. They seem to be the best way to prevent unwanted pregnancies that would otherwise result from sexual unions between two people unprepared for the commitment of raising any or additional children. It almost goes without saying that the more effective and available contraceptives become, the less likely women who wish to avoid pregnancy will become pregnant and the fewer induced abortions they will seek. In reality, the information available concerning abortions and the women who obtain them points to a different conclusion. The more effective and available contraceptives become in a society, the more widespread the practice of induced abortions becomes. On the other hand, natural family planning has been associated with fewer induced abortions when an unplanned pregnancy results. This paper will present a sample of the information available, attempt to draw conclusions, and discuss the possible reasons that contraceptives are unavoidably linked to increasing numbers of induced abortions and that, conversely, natural family planning is associated with very few or no induced abortions. </jats:p