Field Theory reformulated without Self-energy Parts. The dressing Operator

The reformulation of field theory for avoiding self-energy parts in the dynamical evolution has been applied successfully in the framework of the Lee model, [M. de Haan. Ann. Phys., 311, 314-349 (2004)] enabling a kinetic extension of the description. The basic ingredient is the recognition of these self-energy parts. [M. de Haan and C. George. Trends in Statistical Physics 3 (2000), 115] The original reversible description is embedded in the new one and appears now as a restricted class of initial conditions. [M. de Haan and C. George. Prog. Theor. Phys.,109, 881-909 (2003)] This program is realized here in the reduced formalism for a scalar field, interacting with a two-level atom, beyond the usual rotating wave approximation. The kinetic evolution operator, previously surmised, [M. de Haan. Physica, A171 (1991), 159] is here derived from first principles, justifying the usual practice in optics where the common use of the so-called pole approximation should no longer be viewed as an approximation but as an alternative description in the appropriate formalism. That model illustrates how some dressing of the atomic levels (and vertices), through an appropriate operator, finds its place naturally into the new formalism since the bare and dressed ground states do no longer coincide. Moreover, finite velocity for field propagation is now possible in all cases, without the presence of precursors for multiple detections.Comment: 55 pages. Revised version for Annals of Physics. Typos and English corrections, references and precisions adde

Exact Markovian kinetic equation for a quantum Brownian oscillator

We derive an exact Markovian kinetic equation for an oscillator linearly coupled to a heat bath, describing quantum Brownian motion. Our work is based on the subdynamics formulation developed by Prigogine and collaborators. The space of distribution functions is decomposed into independent subspaces that remain invariant under Liouville dynamics. For integrable systems in Poincar\'e's sense the invariant subspaces follow the dynamics of uncoupled, renormalized particles. In contrast for non-integrable systems, the invariant subspaces follow a dynamics with broken-time symmetry, involving generalized functions. This result indicates that irreversibility and stochasticity are exact properties of dynamics in generalized function spaces. We comment on the relation between our Markovian kinetic equation and the Hu-Paz-Zhang equation.Comment: A few typos in the published version are correcte

Specialization of neural mechanisms underlying face recognition in human infants

Newborn infants respond preferentially to simple face-like patterns, raising the possibility that the face-specific region, identified in the adult cortex are functioning from birth. We sought to evaluate this hypothesis by characterizing the specificity Of infants' electrocortical responses to faces in two ways: (1) comparing responses to faces of humans with those to faces of nonhuman primates; and 2) comparing responses to upright and inverted faces. Adults' face-responsive N170 event-related potential (ERP) component showed specificity to upright human faces that was not observable at any point in the ERPs Of infants. A putative "infant N170" did show sensitivity to the species of the face, but the orientation of the face did not influence processing until a later stage. These findings suggest a process of gradual specialization of cortical face processing systems during postnatal development

Met moeite lage kostprijs in 2000

Dit artikel laat zien hoe de kostprijs in 2000 is opgebouwd. Het maakt een vergelijking met praktijkbedrijven

Responding to Gender-based Violence in Scotland: The Scope of the Gender Equality Duty to Drive Cultural and Practical Change

This piece of research has its roots in well-established policy debates in Scotland. Following the passage of the Criminal Justice (Scotland) Act 2003, which introduced a new statutory aggravation for crimes motivated by religious prejudice, the then Scottish Executive convened a working group to explore and make recommendations on whether there was a case for similar provision for other social groups. The report and recommendations of the Hate Crime Working Group, published in 2004, recognised that the debate to introduce gender aggravation was one of the most contested issues which it had looked at, but it did not believe that at that stage it could recommend introducing such a provision. These debates re-emerged with Patrick Harvie’s member’s bill which was to become the Offences (Aggravation by Prejudice) (Scotland) Act 2009. The Equality and Human Rights Commission, along with many organisations in the women’s sector in Scotland, stated in its evidence on the bill that it did not believe that a statutory gender aggravation would be an effective additional criminal justice response to identifying and tackling crime motivated by gender prejudice. This of course begs the question about what is required to better address these types of crime. This piece of research, undertaken for the EHRC by the Scottish Centre for Crime and Justice Research, aims to be a useful contribution to this debate. It explores some of the arguments for and against a gender aggravation in Scots criminal law before considering the evidence thus far of the impact the Gender Equality Duty (GED) has had on Scotland’s criminal justice system, and makes a number of useful recommendations for the future. The EHRC subscribes to a gendered model of violence against women, which sees it as both a cause and consequence of wider gender inequality. We hope this report can help inform ongoing policy debate on criminal justice agencies’ response to violence against women, particularly in light of the new single equality duty which Scottish Ministers will in due course place on Scottish public authorities under powers conferred on them by the Equality Act 2010. We believe that the appropriate regulatory framework for public bodies working in this area is one of the prerequisites for further improving on Scotland’s record of identifying and tackling gender-based crime

Asymmetric Mach-Zehnder fiber interferometer test of the anisotropy of the speed of light

Two optical fiber Mach-Zehnder interferometers were constructed in an environment with a temperature stabilization of better than 1 mK per day. One interferometer with a length of 2 m optical fiber in each arm with the main direction of the arms parallel to each other. A path (length 175 mm) filled with atmospheric air is inserted in one arm. Another interferometer with a length of 2 m optical fiber in each parallel arm acts as a control. In each arm 1 m of fiber was wound around a ring made of piezo material enabling the control of the length of the arms by means of a voltage. The influence of rotation of the interferometers at the Earth surface on the observed phase differences was determined. For one interferometer (with the air path) it was found that the phase difference depends on the azimuth of the interferometer. For the other one no relevant dependence on the azimuth has been measured.Comment: 6 pages, 6 figure

Giant magnetoresistance in Co/Cu multilayers sputtered with Kr

This paper presents some results of magnetoresistance measurements on Kr-sputter-deposited Co/Cu multilayers. We find that Co/Cu MLs sputtered with Kr gas show a larger GMR effect than those sputtered with Ar gas

Lage kostprijs biedt ruimte voor de toekomst (1)

In dit artikel volgen we de geldstroom van netto bedrijfsresultaat naar netto kasstroom op het gemiddelde Nederlandse melkveebedrijf dat qua omvang en intensiteit vergelijkbaar is met het lagekostenbedrijf

Lage kostprijs biedt ruimte voor de toekomst (2)

In dit tweede artikel volgen we de geldstroom uit eigen bedrijf van netto bedrijfsresultaat naar netto kasstroom op het Lagekostenbedrijf en vergelijken dit met de praktijk