Classical Spinning Branes in Curved Backgrounds

The dynamics of a classical branelike object in a curved background is derived from the covariant stress-energy conservation of the brane matter. The world sheet equations and boundary conditions are obtained in the pole-dipole approximation, where nontrivial brane thickness gives rise to its intrinsic angular momentum. It is shown that intrinsic angular momentum couples to both, the background curvature and the brane orbital degrees of freedom. The whole procedure is manifestly covariant with respect to spacetime diffeomorphisms and world sheet reparametrizations. In addition, two extra gauge symmetries are discovered and utilized. The examples of the point particle and the string in 4 spacetime dimensions are analyzed in more detail. A particular attention is paid to the Nambu-Goto string with massive spinning particles attached to its ends

Operational interpretation of the vacuum and process matrices for identical particles

This work overviews the single-particle two-way communication protocol recently introduced by del Santo and Daki\'c (dSD), and analyses it using the process matrix formalism. We give a detailed account of the importance and the operational meaning of the interaction of an agent with the vacuum -- in particular its role in the process matrix description. This raises the issue of counting such operations in an operational manner. Motivated by this analysis, we extend the process matrix formalism to Fock space using the framework of second quantisation, in order to characterise protocols with an indefinite number of identical particles.Comment: 9 pages (double column), 3 figure

Influencing collective moral judgement by changing ethical culture in tourism industry: The case of Slovenia

Moral reasoning is a process of determining what is wrong and what is right from a moral point of view. Four components of moral reasoning are: moral sensitivity, moral judgement, moral motivation and moral character. Our research presented here is focused on the second component – moral judgement. Moral judgement refers to reaching an appropriate decision from the moral perspective in response to a given situation or a problem. Individuals can decide between focusing on themselves (egoistic moral judgement) or others (benevolence – disposition to be good) in their decision-making process. While the environment influences us, individuals differ within this spectrum. Thus, the prevalent collective moral judgement in any given company is under the influence of company characteristics and its ethical culture. This paper examines the effects of the ethical culture of Slovenian companies in the tourism industry on the collective moral judgement of their employees and identifies those ethical culture dimensions that could alter the collective moral judgement of the employees in the tourism industry. The results were collected through quantitative empirical research. The research was conceptualised and analysed with reference to Kaptein\u27s (1998) Corporate Ethical Virtues Model, comprised of seven ethical culture dimensions: clarity, congruency, feasibility, supportability, transparency, discussability and sanctionability. Results of our research have shown that if these dimensions of ethical culture are expressed more highly, collective moral judgement tends to increase its focus on how decisions will affect others. Suggestions for the management of tourist companies, as well as the Slovenian national tourist organisation (STO), have been proposed on the basis of the results of this paper

Spinning branes in Riemann-Cartan spacetime

We use the conservation law of the stress-energy and spin tensors to study the motion of massive brane-like objects in Riemann-Cartan geometry. The world-sheet equations and boundary conditions are obtained in a manifestly covariant form. In the particle case, the resultant world-line equations turn out to exhibit a novel spin-curvature coupling. In particular, the spin of a zero-size particle does not couple to the background curvature. In the string case, the world-sheet dynamics is studied for some special choices of spin and torsion. As a result, the known coupling to the Kalb-Ramond antisymmetric external field is obtained. Geometrically, the Kalb-Ramond field has been recognized as a part of the torsion itself, rather than the torsion potential

A finiteness bound for the EPRL/FK spin foam model

We show that the EPRL/FK spin foam model of quantum gravity has an absolutely convergent partition function if the vertex amplitude is divided by an appropriate power $p$ of the product of dimensions of the vertex spins. This power is independent of the spin foam 2-complex and we find that $p>2$ insures the convergence of the state sum. Determining the convergence of the state sum for the values $0 \le p \le 2$ requires the knowledge of the large-spin asymptotics of the vertex amplitude in the cases when some of the vertex spins are large and other are small.Comment: v6: published versio

Synthesis and structural characterization of Cd(II) complexes with 2-acetylpyridine-aminoguanidine - a novel coordination mode

The structures of the first two complexes with bidentate coordination of aminoguanidine Schiff base, i.e., 2-acetylpyridine-aminoguanidine (L), are reported. The complex of the formula [Cd2Cl6(HL)2] (1) was obtained in the reaction of warm aqueous solutions of chloride salts of Cd(II), Zn(II) and the ligand, while the reaction of cadmium bromide and the ligand in the presence of deprotonating agent as well as ammonium thiocyanate resulted in the formation of the complex in which Schiff base has both the role of the ligand and the counterion, viz., [HL][Cd(HL)(NCS)2XY]·H2O (2), where X is Cl- or Br-, and Y Br- or SCN-. The complexes were characterized by IR spectroscopy, elemental analysis, conductometric measurements and single crystal X-ray diffraction. The unusual bidentate coordination of the Schiff base lead to significant changes in the geometry of this molecule (from almost planar in free form and as a tridentate ligand to twisted as a bidentate ligand). Besides, in complex 1 relatively rare bridging coordination of Cl- in octahedral Cd(II) is found, while the crystal structure of complex 2 exhibits substitutional disorder, and contains four different anions: [Cd(HL)(NCS)2Br(SCN)]- (ca. 61 %), [Cd(HL)(NCS)2Cl(SCN)]- (ca. 35 %), [Cd(HL)(NCS)2Br2]- (ca. 3 %) and [Cd(HL)(NCS)2ClBr]- (ca. 1 %)

Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II) bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC). Crystal structure of [Cu(PLITSC−H)H2O]Br•H2O

The synthesis and structural characterization of a square-planar copper(II) complex with pyridoxal S-methylisothiosemicarbazone (PLITSC) of the formula [Cu(PLITSC−H)H2O]Br•H2O (1) as the first Cu(II) complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSC)Br2] (2) and [Cu(PLITSC)Br(MeOH)]Br (3) were characterized by elemental analysis, IR and electronic spectra and also by the methods of thermal analysis, conductometry and magnetochemistry. [Projekat Pokrajisnkog sekretarijata za nauku i tehnoloski razvoj Vojvodine i Ministarstva nauke Republike Srbije, br. 172014

Classical String in Curved Backgrounds

The Mathisson-Papapetrou method is originally used for derivation of the particle world line equation from the covariant conservation of its stress-energy tensor. We generalize this method to extended objects, such as a string. Without specifying the type of matter the string is made of, we obtain both the equations of motion and boundary conditions of the string. The world sheet equations turn out to be more general than the familiar minimal surface equations. In particular, they depend on the internal structure of the string. The relevant cases are classified by examining canonical forms of the effective 2-dimensional stress-energy tensor. The case of homogeneously distributed matter with the tension that equals its mass density is shown to define the familiar Nambu-Goto dynamics. The other three cases include physically relevant massive and massless strings, and unphysical tahyonic strings.Comment: 12 pages, REVTeX 4. Added a note and one referenc