A few more moments to finance theory: introducing higher moments in investment theory and econometrics

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Langevin dynamics of the deconfinement transition for pure gauge theory

We investigate the effects of dissipation in the deconfinement transition for pure SU(2) and SU(3) gauge theories. Using an effective theory for the order parameter, we study its Langevin evolution numerically. Noise effects are included for the case of SU(2). We find that both dissipation and noise have dramatic effects on the spinodal decomposition of the order parameter and delay considerably its thermalization. For SU(3) the effects of dissipation are even larger than for SU(2).

CdSe/CdTe interface band gaps and band offsets calculated using spin-orbit and self-energy corrections

We performed ab initio calculations of the electronic structures of bulk CdSe and CdTe, and their interface band alignments on the CdSe in-plane lattice parameters. For this, we employed the LDA-1/2 self-energy correction scheme [L.G. Ferreira, M. Marques, L.K. Teles, Phys. Rev. B 78 (2008) 125116] to obtain corrected band gaps and band offsets. Our calculations include the spin-orbit effects for the bulk cases, which have shown to be of importance for the equilibrium systems and are possibly degraded in these strained semiconductors. Therefore, the SO showed reduced importance for the band alignment of this particular system. Moreover, the electronic structure calculated along the transition region across the CdSe/CdTe interface shows an interesting non-monotonic variation of the band gap in the range 0.8-1.8 eV, which may enhance the absorption of light for corresponding frequencies at the interface between these two materials in photovoltaic applications. (C) 2012 Elsevier B.V. All rights reserved.

Evidence of the participation of electronic excited states in the mechanism of positronium formation in substitutional Tb1-xEux(dpm)(3) solid solutions studied by optical and positron annihilation spectroscopies

Positronium formation in the bimary molecular solid solutions Tb1-xEux (dpm)(3) (dpm = dipivaloylmethanate) has been investigated. A strong linear correlation between the D-5(4) Tb(III) energy level excited state lifetime and the positronium formation probability has been observed. This correlation indicates that the ligand-to-metal charge transfer LMCT states act in both luminescence quenching and positronium formation inhibition, as previously proposed. A kinetic mechanism is proposed to explain this correlation and shows that excited electronic states have a very important role in the positronium formation mechanism.

Coupled-Cluster-Berechnungen von Parametern der Kernspin-Resonanz-Spektroskopie

Coupled-Cluster-Berechnungen von Parametern derKernspin-Resonanz-Spektroskopie Dissertationsschrift von Alexander A.Auer, Mainz 2002 Im Rahmen einer Studie der Berechnung von 13C-Verschiebungenwerdendie Einfluesse von Elektronenkorrelation, Basissatz,Gleichgewichtsgeometrie sowie Schwingungs- und Rotationseffekten separat betrachtet.Dabei zeigt sich, dass dieCoupled-Cluster-Singles-Doubles-Methode mitstoerungstheoretischer Behandlung der Dreifachanregungen(CCSD(T)) mit entsprechend grossen Basissaetzen bei Beruecksichtigung derNullpunktsschwingungseffekte Ergebnisse mit ca. 1 ppm Abweichung zum Experiment liefert. Eine Analyse der Elektronenkorrelationseffekte beiCoupled-Cluster- (CC-) Berechnungen von indirekten Spin-Spin-Kopplungskonstanten zeigt, dassCC-Methoden mit Hartree-Fock-Orbitalrelaxation zur Berechnung derKopplungskonstanten ungeeignet sind. Eine Loesung ist die Verwendung unrelaxierter CC-Methoden,in denendie HF-Orbitalrelaxation aus der Berechnung der gestoertenWellenfunktion ausgeschlossen wird. Full-Configuration-Interaction-Berechnungen fuer Borhydridzeigen,dass auf CC-Singles-Doubles-Niveau (CCSD) 94% und aufCC-Singles-Doubles-Triples-Niveau (CCSDT) 99% der Korrelationseffekte beschrieben werden. Weiterhin istdie Beruecksichtigung der Nullpunktsschwingung sowie die Wahl eines ausreichend grossen Basissatzes wichtig. Auf Grundlage der vorangegangenen Studien werden im letztenTeil zwei Beispiele zur Anwendung hochgenauer Berechnungen vonNMR-Parametern vorgestellt.Im Rahmen einer Studie der Spin-Spin-Kopplungskonstanten vonCyclopentan wird eine Karplus-Beziehungzwischen den Kopplungskonstanten und der Konformation desMolekuels aufgestellt, desweiteren werden die NMR-Parameter von Methylidinphosphanuntersucht.

Direct observation of mixed-parity excited states in surface-passivated PbS nanocrystals

Photoluminescent emission is observed from surface-passivated PbS nanocrystals following the two-photon excitation of high-energy excitonic states. The emission appears directly at the excitation energy with no detectable Stokes-shift for a wide range of excitation energies. The observation of direct emission from states excited by two-photon absorption indicates that the parity of the excited states of surface-passivated PbS nanocrystals is partially mixed.

The EU's support for democratic governance in the Eastern neighbourhood:the role of transition experience from the New Member States

The European Union seems to place an increasing rhetorical emphasis on harnessing the transition experience of the new member states. This article examines whether the EU actually makes use of this experience in its promotion of democratic governance in the eastern neighbourhood. The main conclusion is that while reform priorities of the EU in the region are aligned with transition experience, the actual participation of actors from the new members in implementing EU-financed projects aimed at promoting democratic governance is limited. This contradiction should be resolved or it will further erode the credibility of the EU's external policies.

Dynamical interplay between ground and excited states in quantum dot laser

Full text: Semiconductor quantum dot lasers are attractive for multipletechnological applications in biophotonics. Simultaneous two-state lasing ofground state (GS) and excited state (ES) electrons and holes in QD lasers ispossible under a certain parameter range. It has already been investigated in steady-stateoperations and in dynamical regimes and is currently a subject of the intesiveresearch. It has been shown that the relaxation frequency in the two-state lasingregime is not a function of the total intensity [1], as could be traditionallyexpected.In this work we study damping relaxation oscillations in QD lasersimultaneously operating at two transitions, and find that under variouspumping conditions, the frequency of oscillations may decrease, increase orstay without change in time as shown in Fig1.The studied QD laser structure wasgrown on a GaAs substrate by molecular-beam epitaxy. The active region includedfive layers of self-assembled InAs QDs separated with a GaAs spacer from a5.3nm thick covering layer of InGaAs and processed into 4mm-wide mesa stripe devices. The 2.5mm long lasers withhigh-and antireflection coatings on the rear and front facets lasesimultaneously at the GS (around 1265nm) and ES (around 1190nm) in the wholerange of pumping. Pulsed electrical pumping obtained from a high power (up to2A current) pulse source was used to achieve high output power operation. We simultaneously detect the total output and merely ES output using aBragg filter transmitting the short-wavelength and reflecting the long-wavelengthradiation. Typical QD does not demonstrate relaxation oscillations frequencybecause of the strong damping [2]. It is confirmed for the low (I<0.68A) andhigh (I>1.2 A) range of the pump currents in our experiments. The situationis different for a short range of the medium currents (0.68A

Energy transfer rates and population inversion investigation of sup(1)Gsub(4) and sup(1)Dsub(2) excited states of Tmsup(3+) in Yb:Tm:Nd:KYsub(3)Fsub(10) crystals

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Population inversion between the sup(3)Hsub(4) and the sup(3)Fsub(4) excited states of Tmsup(3+) investigated by means of numerical solutions of the rate equations system in Tmsup(3+)-doped and Tmsup(3+), Hosup(3+)-codoped fluoride glasses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ab initio benchmark study for the oxidative addition of CH4 to Pd: importance of basis-set flexibility and polarization

To obtain a state-of-the-art benchmark potential energy surface (PES) for the archetypal oxidative addition of the methane C-H bond to the palladium atom, we have explored this PES using a hierarchical series of ab initio methods (Hartree-Fock, second-order Møller-Plesset perturbation theory, fourth-order Møller-Plesset perturbation theory with single, double and quadruple excitations, coupled cluster theory with single and double excitations (CCSD), and with triple excitations treated perturbatively [CCSD(T)]) and hybrid density functional theory using the B3LYP functional, in combination with a hierarchical series of ten Gaussian-type basis sets, up to g polarization. Relativistic effects are taken into account either through a relativistic effective core potential for palladium or through a full four-component all-electron approach. Counterpoise corrected relative energies of stationary points are converged to within 0.1-0.2 kcal/mol as a function of the basis-set size. Our best estimate of kinetic and thermodynamic parameters is -8.1 (-8.3) kcal/mol for the formation of the reactant complex, 5.8 (3.1) kcal/mol for the activation energy relative to the separate reactants, and 0.8 (-1.2) kcal/mol for the reaction energy (zero-point vibrational energy-corrected values in parentheses). This agrees well with available experimental data. Our work highlights the importance of sufficient higher angular momentum polarization functions, f and g, for correctly describing metal-d-electron correlation and, thus, for obtaining reliable relative energies. We show that standard basis sets, such as LANL2DZ+ 1f for palladium, are not sufficiently polarized for this purpose and lead to erroneous CCSD(T) results. B3LYP is associated with smaller basis set superposition errors and shows faster convergence with basis-set size but yields relative energies (in particular, a reaction barrier) that are ca. 3.5 kcal/mol higher than the corresponding CCSD(T) values

Delta(1232) isobar excitations in nuclear many-body systems from varios NN interactions.

Delta isobar components in the nuclear many-body wave function are investigated for the deuteron, light nuclei (16O), and infinite nuclear matter within the framework of the coupled-cluster theory. The predictions derived for various realistic models of the baryon-baryon interaction are compared to each other. These include local (V28) and nonlocal meson exchange potentials (Bonn2000) but also a model recently derived by the Salamanca group accounting for quark degrees of freedom. The characteristic differences which are obtained for the NDelta and Delta Delta correlation functions are related to the approximation made in deriving the matrix elements for the baryon-baryon interaction.