Constraints on Space-Time Torsion from Hughes-Drever Experiments

The coupling of space-time torsion to the Dirac equation leads to effects on the energy levels of atoms which can be tested by Hughes-Drever type experiments. Reanalysis of these experiments carried out for testing the anisotropy of mass and anomalous spin couplings can lead to the till now tightest constraint on the axial torsion by $K \leq 1.5 . 10^{-15} m^{-1}$.Comment: 10 pages, LaTex, To appear in Phys.Lett.

The Emergence of the Entrepreneurial Society

Previous generations enjoyed the security of lifelong employment with a sole employer. Public policy and social institutions reinforced that security by producing a labor force content with mechanized repetition in manufacturing plants, and creating loyalty to one employer for life. This is no longer the case. Globalisation and new technologies have triggered a shift away from capital and toward knowledge. In today's global economy, where jobs and factories can be moved quickly to low-cost locations, the competitive advantage has shifted to ideas, insights, and innovation. But it is not enough just to have new ideas. It takes entrepreneurs to actualize them by championing them to society. Entrepreneurship has emerged as the proactive response to globalisation. This study identifies the positive, proactive response to globalisation-the entrepreneurial society, where change is the cutting edge and routine work is inevitably outsourced. Under the managed economy of the cold war era, government policies around the world supported big business, while small business was deemed irrelevant and largely ignored. This presentation explains the fundamental policy revolution under way, shifting the focus to technology and knowledge-based entrepreneurship, where start-ups and small business have emerged as the driving force of innovation, jobs, competitiveness and growth. The role of the university has accordingly shifted from tangential to a highly valued seedbed for coveted new ideas with the potential to create not just breathtaking new ventures, but also entire new industries. By understanding the shift from the managed economy and the emergence of the entrepreneurial society, individuals, businesses, and communities can learn how to proactively harness the opportunities afforded by globalisation in this new entrepreneurial society.

The Emergence of the Entrepreneurial Society: The 2008 Geary Lecture

This is the text of the 2008 Geary Lecture, an annual lecture in honour of Roy Geary delivered at the Economic and Social Research Institute in Dublin.

Relation between energy shifts and relaxation rates for a small system coupled to a reservoir

For a small system the coupling to a reservoir causes energy shifts as well as transitions between the system's energy levels. We show for a general stationary situation that the energy shifts can essentially be reduced to the relaxation rates. The effects of reservoir fluctuations and self reaction are treated separately. We apply the results to a two-level atom coupled to a reservoir which may be the vacuum of a radiation field.Comment: 6 pages, Latex, to appear in Phys. Lett.

From small business promotion to creating an entrepreneurial society

Mittelstandspolitik, Unternehmer, Wissenstransfer, EU-Staaten, Deutschland, Small business policy, Entrepreneurs, Knowledge transfer, EU countries, Germany

Spontaneous excitation of an accelerated multilevel atom in dipole coupling to the derivative of a scalar field

We study the spontaneous excitation of an accelerated multilevel atom in dipole coupling to the derivative of a massless quantum scalar field and separately calculate the contributions of the vacuum fluctuation and radiation reaction to the rate of change of the mean atomic energy of the atom. It is found that, in contrast to the case where a monopole like interaction between the atom and the field is assumed, there appear extra corrections proportional to the acceleration squared, in addition to corrections which can be viewed as a result of an ambient thermal bath at the Unruh temperature, as compared with the inertial case, and the acceleration induced correction terms show anisotropy with the contribution from longitudinal polarization being four times that from the transverse polarization for isotropically polarized accelerated atoms. Our results suggest that the effect of acceleration on the rate of change of the mean atomic energy is dependent not only on the quantum field to which the atom is coupled, but also on the type of the interaction even if the same quantum scalar field is considered.Comment: 11 pages, no figure

Evolution of a qubit under the influence of a succession of unsharp measurements

We investigate the evolution of a single qubit subject to a continuous unitary dynamics and an additional interrupting influence which occurs periodically. One may imagine a dynamically evolving closed quantum system which becomes open at certain times. The interrupting influence is represented by an operation, which is assumed to equivalently describe a non-selective unsharp measurement. It may be decomposed into a positive operator, which in case of a measurement represents the pure measurement part, followed by an unitary back-action operator. Equations of motion for the state evolution are derived in the form of difference equations. It is shown that the 'free' Hamiltonian is completed by an averaged Hamiltonian, which goes back to the back-action. The positive operator specifies a decoherence rate and results in a decoherence term. The continuum limit to a master equation is performed. The selective evolution is discussed and correcting higher order terms are worked out in an Appendix.Comment: 19 pages, no figure