Bremsstrahlung Radiation At a Vacuum Bubble Wall

When charged particles collide with a vacuum bubble, they can radiate strong electromagnetic waves due to rapid deceleration. Owing to the energy loss of the particles by this bremsstrahlung radiation, there is a non-negligible damping pressure acting on the bubble wall even when thermal equilibrium is maintained. In the non-relativistic region, this pressure is proportional to the velocity of the wall and could have influenced the bubble dynamics in the early universe.Comment: 6 pages, 2 figures, revtex, to appear in JKP

Quantum Separability of the vacuum for Scalar Fields with a Boundary

Using the Green's function approach we investigate separability of the vacuum state of a massless scalar field with a single Dirichlet boundary. Separability is demonstrated using the positive partial transpose criterion for effective two-mode Gaussian states of collective operators. In contrast to the vacuum energy, entanglement of the vacuum is not modified by the presence of the boundary.Comment: 4 pages, 1 figure, Revtex, minor corrections. submitted to Phy. Rev.

Quantum mechanics emerges from information theory applied to causal horizons

It is suggested that quantum mechanics is not fundamental but emerges from classical information theory applied to causal horizons. The path integral quantization and quantum randomness can be derived by considering information loss of fields or particles crossing Rindler horizons for accelerating observers. This implies that information is one of the fundamental roots of all physical phenomena. The connection between this theory and Verlinde's entropic gravity theory is also investigated.Comment: REvtex4-1, 6pages, 2 figures, final versio

The characterization and composition of bacterial communities in soils blended with spent foundry sand

The purpose of this research was to characterize the structure and composition of bacterial communities in sandy loam and silty clay soils amended with 30% spent sand from iron, aluminum, and steel foundries. All spent foundry sand (SFS) blends were grown with or without perennial ryegrass and samples were collected at 4 weeks and 6 months. Regions of the 16S rRNA gene were amplified using PCR and subsequently analyzed by DGGE and sequenced for bacterial identification and phylogenetic classification. Cluster analyses of PCR-DGGE banding patterns revealed that SFS blends from week 4 and month 6 produced unique clusters, with most ryegrass treatments clustering away from those without ryegrass. The diversity of the bacterial community revealed that it was generally higher in the SFS blends without ryegrass. By month 6 in treatments without ryegrass, the diversity in the sandy loam blends was similar to the control, while the diversity in all silty clay blends was greater than the control. Phylogenetic analysis of bacterial isolates (total of 309) from the SFS blends showed that they were dominated by Actinobacteria (46%), Proteobacteria (29%), and Bacilli (20%), with fewer numbers belonging to Bacteroidetes (5%). While the addition of SFS to soil does bring about bacterial community level changes, these changes are similar to that of blending soil with clean silica sand

Gravity from Quantum Information

It is suggested that the Einstein equation can be derived from Landauer's principle applied to an information erasing process at a local Rindler horizon and Jacobson's idea linking the Einstein equation with thermodynamics. When matter crosses the horizon, the information of the matter disappears and the horizon entanglement entropy increases to compensate the entropy reduction. The Einstein equation describes an information-energy relation during this process, which implies that entropic gravity is related to the quantum entanglement of the vacuum and has a quantum information theoretic origin.Comment: 7 pages, revtex4-1, 2 figures, recent supporting results adde

Optimality of minimum-error discrimination by the no-signalling condition

In this work we relate the well-known no-go theorem that two non-orthogonal (mixed) quantum states cannot be perfectly discriminated, to the general principle in physics, the no-signalling condition. In fact, we derive the minimum error in discrimination between two quantum states, using the no-signalling condition.Comment: 4 pages, 1 figur

Интернационализация подготовки научных кадров в развитых европейских странах:проблемы и уроки

Показаны формы международного сотрудничества в рамках интернационализации докторского образования, стратегии интернационализации высшего образования в целом и докторского в частности. Описан накопленный опыт, сформулированы основные уроки и полезные идеи, вытекающие из него.Показано форми міжнародного співробітництва у рамках інтернаціоналізації докторської освіти, стратегії інтернаціоналізації вищої освіти загалом та докторської зокрема. Описано накопичений досвід, сформульовано основні уроки та корисні ідеї, що випливають з нього.Forms of international cooperation in internationalization of doctoral education, strategies of internationalization in higher education in general and doctoral education in particular are shown. Experiences accumulated in this field are described; main lessons and useful ideas born from the experiences are outlined

Zero Cosmological Constant and Nonzero Dark Energy from Holographic Principle

It is shown that the first law of thermodynamics and the holographic principle applied to an arbitrary large cosmic causal horizon naturally demand the zero cosmological constant and non-zero dynamical dark energy in the form of the holographic dark energy. Semiclassical analysis shows that the holographic dark energy has a parameter $d=1$ and an equation of state comparable to current observational data, if the entropy of the horizon saturates the Bekenstein-Hawking bound. This result indicates that quantum field theory should be modified at large scale to explain dark energy. The relations among dark energy, quantum vacuum energy and entropic gravity are also discussed.Comment: Revtex 7 pages 2 fig

On the Origin of Entropic Gravity and Inertia

It was recently suggested that quantum field theory is not fundamental but emerges from the loss of phase space information about matter crossing causal horizons. Possible connections between this formalism and Verlinde's entropic gravity and Jacobson's thermodynamic gravity are proposed. The holographic screen in Verlinde's formalism can be identified as local Rindler horizons and its entropy as that of the bulk fields beyond the horizons. This naturally resolves some issues on entropic gravity. The quantum fluctuation of the fields is the origin of the thermodynamic nature of entropic gravity. It is also suggested that inertia is related to dragging Rindler horizons.Comment: 9 pages, revtex4-1, 3 figures, accepted for publication in Foundations of Physic