Primordial nucleosynthesis as a probe of fundamental physics parameters

We analyze the effect of variation of fundamental couplings and mass scales on primordial nucleosynthesis in a systematic way. The first step establishes the response of primordial element abundances to the variation of a large number of nuclear physics parameters, including nuclear binding energies. We find a strong influence of the n-p mass difference (for the 4He abundance), of the nucleon mass (for deuterium) and of A=3,4,7 binding energies (for 3He, 6Li and 7Li). A second step relates the nuclear parameters to the parameters of the Standard Model of particle physics. The deuterium, and, above all, 7Li abundances depend strongly on the average light quark mass hat{m} \equiv (m_u+m_d)/2. We calculate the behaviour of abundances when variations of fundamental parameters obey relations arising from grand unification. We also discuss the possibility of a substantial shift in the lithium abundance while the deuterium and 4He abundances are only weakly affected.Comment: v2: 34 pages, 2 figures, typo in last GUT scenario corrected, added discussion and graph of nonlinear behaviour in GUT scenarios, added short section discussing binding of dineutron and 8Be, refs added, conclusions unaltered. Accepted for publication, Phys. Rev.

Recommendations and illustrations for the evaluation of photonic random number generators

The never-ending quest to improve the security of digital information combined with recent improvements in hardware technology has caused the field of random number generation to undergo a fundamental shift from relying solely on pseudo-random algorithms to employing optical entropy sources. Despite these significant advances on the hardware side, commonly used statistical measures and evaluation practices remain ill-suited to understand or quantify the optical entropy that underlies physical random number generation. We review the state of the art in the evaluation of optical random number generation and recommend a new paradigm: quantifying entropy generation and understanding the physical limits of the optical sources of randomness. In order to do this, we advocate for the separation of the physical entropy source from deterministic post-processing in the evaluation of random number generators and for the explicit consideration of the impact of the measurement and digitization process on the rate of entropy production. We present the Cohen-Procaccia estimate of the entropy rate $h(\epsilon,\tau)$ as one way to do this. In order to provide an illustration of our recommendations, we apply the Cohen-Procaccia estimate as well as the entropy estimates from the new NIST draft standards for physical random number generators to evaluate and compare three common optical entropy sources: single photon time-of-arrival detection, chaotic lasers, and amplified spontaneous emission

Deformation of the Macumber Formation, Antigonish Basin, Nova Scotia: implications for the Ainslie Detachment

The Antigonish Basin is one of several Carboniferous structural basins in northeastern Nova Scotia, the evolution of which have been cited as evidence for major detachment faulting within the Vis. Windsor Group of Maritime Canada. Evidence of extension in the Antigonish Basin takes the form of a major subhorizontal structure that closely follows the basin margins and has been interpreted as part of the regional Ainslie Detachment. Placed at the top of the basal Macumber Formation and reportedly characterized by several metres of calc-mylonite, the detachment is considered to have accommodated 10—25 km of westward transport of the evaporitic Windsor and overlying Mabou groups during the late Namurian-early Westphalian. However, deformation within the Macumber Formation limestone immediately beneath the detachment surface suggests local extension of Vis. age. Recumbent intraformational folds are overlain by depositional breccias that contain previously folded fragments and are themselves recumbently folded. These relationships suggest repeated movement that began soon after limestone deposition. Furthermore, fold asymmetry and the orientation of calcite veins and small-scale normal faults suggest variable directions of extension that converge on the centre of the basin located in St. Georges Bay. While these data do not preclude the existence of the Ainslie Detachment, they suggest that the Macumber Formation in the Antigonish Basin records an earlier episode of deformation that occurred in response to local gravity sliding rather than to movement on a regional detachment surface. RESUMÉ Le bassin d Antigonish constitue l un d une série de bassins structuraux du Carbonifère dans le nord-ouest de la Nouvelle-Écosse don t l évolution a été citée comme preuve d une dislocation importante par détachement à l intérieur du groupe viséen de Windsor dans les provinces Maritimes. On relève une preuve du prolongement dans le bassin d Antigonish sous la forme d une structure subhorizontale importante qui suit de près les limites du bassin et qui a été interprétée comme une partie du détachement régional d Ainslie. On estime que le détachement, situé au sommet de la Formation basale de Macumber et caractérisé, d après ce qu on dit, par plusieurs mètres de mylonite calcique, a permis le transport vers l ouest sur dix à 25 kilomètres des groupes sus-jacent de Mabou et évaporitique de Windsor au cours de la période du Namurien tardif-Westphalien précoce. La déformation à l intérieur du calcaire de la Formation de Macumber immédiatement au-dessous de la surface du détachement, laisse toutefois supposer un prolongement local à l époque du Viséen. Les plis intraformationnels couchés sont recouverts de brèches de sedimentation renfermant des fragments antérieurement pliés qui sont eux-mêmes repliés sur un plan axial horizontal. Ces rapports permettent de supposer un mouvement répété qui a débuté peu après la sédimentation du calcaire. De plus, l asymétrie des plis et l orientation des filons de calcite et des failles normales de petite échelle laissent supposer des orientations de prolongation variables qui convergent vers le centre du bassin situé dans la baie de St. Georges. Même si ces données n écartent pas la possibilité de l existence du détachement d Ainslie, elles permettent de supposer que la Formation de Macumber dans le bassin d Antigonish évoque un épisode plus hâtif de déformation, survenu à la suite d un glissement gravitationnel local plutôt que d un déplacement à la surface d un détachement régional

Complex Dynamics and Synchronization of Delayed-Feedback Nonlinear Oscillators

We describe a flexible and modular delayed-feedback nonlinear oscillator that is capable of generating a wide range of dynamical behaviours, from periodic oscillations to high-dimensional chaos. The oscillator uses electrooptic modulation and fibre-optic transmission, with feedback and filtering implemented through real-time digital-signal processing. We consider two such oscillators that are coupled to one another, and we identify the conditions under which they will synchronize. By examining the rates of divergence or convergence between two coupled oscillators, we quantify the maximum Lyapunov exponents or transverse Lyapunov exponents of the system, and we present an experimental method to determine these rates that does not require a mathematical model of the system. Finally, we demonstrate a new adaptive control method that keeps two oscillators synchronized even when the coupling between them is changing unpredictably.Comment: 24 pages, 13 figures. To appear in Phil. Trans. R. Soc. A (special theme issue to accompany 2009 International Workshop on Delayed Complex Systems

Florida manatee

The South Carolina Department of Natural Resources published guides to many threatened animals living in the state. This guide gives information about the Florida manatee, including description, status, habitat, conservation challenges & recommendations, and measures of success

Cannonball Jellyfish

The South Carolina Department of Natural Resources published guides to many threatened animals living in the state. This guide gives information about the Cannonball Jellyfish, including description, status, habitat, conservation challenges & recommendations, and measures of success

Acoustic wave studies during fast ion beam interactions with solds

Ion beam material modification is currently being used for several important technological applications such as semiconductor doping [1], surface modification of metals [2], cold etching [1], micro machining [1] and material analysis [3]. Ion beam processing has many advantages [4]. The speed, homogeneity and reproducibility of the doping process are easily controlled. Tight control of the number of doping atoms is possible. Low purity dopants can be used. The target can be kept at low temperatures allowing for low melting temperature materials to be modified. Simple masking methods can be employed and doping can be performed through passive films. Low penetration depths can be achieved and multiple implantations can produce varied doping profiles. Devices with small dimensions can be manufactured due to the small size of the ion beam. Since ion implantation is not an equilibrium process, equilibrium solubility limits of the ion species in the target material can be exceeded. There are some disadvantages of this type of doping process. Damage is caused to the crystal structure creating defects. Implantation is limited to near-surface regions and theoretical profiles can be difficult to obtain due to effects of channeling and diffusion [5]

Using Synchronization for Prediction of High-Dimensional Chaotic Dynamics

We experimentally observe the nonlinear dynamics of an optoelectronic time-delayed feedback loop designed for chaotic communication using commercial fiber optic links, and we simulate the system using delay differential equations. We show that synchronization of a numerical model to experimental measurements provides a new way to assimilate data and forecast the future of this time-delayed high-dimensional system. For this system, which has a feedback time delay of 22 ns, we show that one can predict the time series for up to several delay periods, when the dynamics is about 15 dimensional.Comment: 10 pages, 4 figure