Intra-EU investment protection in a post-Achmea world

In Commission v Hungary, the CJEU found that Hungary failed to fulfil its obligations under EU law by restricting EU investors’ rights. This Perspective considers what the judgment means for the future of intra-EU investment protection, and whether it will approximate the level of protection currently enjoyed under investor-state arbitration

Anomalous expansion and phonon damping due to the Co spin-state transition in RCoO_3 with R = La, Pr, Nd and Eu

We present a combined study of the thermal expansion and the thermal conductivity of the perovskite series RCoO_3 with R = La, Nd, Pr and Eu. The well-known spin-state transition in LaCoO_3 is strongly affected by the exchange of the R ions due to their different ionic radii, i.e. chemical pressure. This can be monitored in detail by measurements of the thermal expansion, which is a highly sensitive probe for detecting spin-state transitions. The Co ions in the higher spin state act as additional scattering centers for phonons, therefore suppressing the phonon thermal conductivity. Based on the analysis of the interplay between spin-state transition and heat transport, we present a quantitative model of the thermal conductivity for the entire series. In PrCoO_3, an additional scattering effect is active at low temperatures. This effect arises from the crystal field splitting of the 4f multiplet, which allows for resonant scattering of phonons between the various 4f levels.Comment: 15 pages including 5 figure

Achmea判决后的欧盟内部投资保护

In Commission v Hungary, the CJEU found that Hungary failed to fulfil its obligations under EU law by restricting EU investors’ rights. This Perspective considers what the judgment means for the future of intra-EU investment protection, and whether it will approximate the level of protection currently enjoyed under investor-state arbitration

Path integral quantization of electrodynamics in dielectric media

In the present paper we study the Faddeev-Popov path integral quantization of electrodynamics in an inhomogenious dielectric medium. We quantize all polarizations of the photons and introduce the corresponding ghost fields. Using the heat kernel technique, we express the heat kernel coefficients in terms of the dielectricity $\epsilon (x)$ and calculate the ultra violet divergent terms in the effective action. No cancellation between ghosts and "non-physical" degrees of freedom of the photon is observed.Comment: 10 pages, Latex, submitted to J.Phys.A, revised (a misprint in the bibliography

使WTO投资便利化框架免受ISDS影响

The authors identify several ways in which an investment facilitation framework for development can be insulated from investor-state dispute settlement provisions in international investment agreements, and suggest specific formulations in this respect

Insulating a WTO Investment Facilitation Framework from ISDS

The authors identify several ways in which an investment facilitation framework for development can be insulated from investor-state dispute settlement provisions in international investment agreements, and suggest specific formulations in this respect

Strong damping of phononic heat current by magnetic excitations in SrCu_2(BO_3)_2

Measurements of the thermal conductivity as a function of temperature and magnetic field in the 2D dimer spin system SrCu$_2$(BO$_3$)$_2$ are presented. In zero magnetic field the thermal conductivity along and perpendicular to the magnetic planes shows a pronounced double-peak structure as a function of temperature. The low-temperature maximum is drastically suppressed with increasing magnetic field. Our quantitative analysis reveals that the heat current is due to phonons and that the double-peak structure arises from pronounced resonant scattering of phonons by magnetic excitations.Comment: a bit more than 4 pages, 2 figures included; minor changes to improve the clarity of the presentatio

Dilatonic current-carrying cosmic strings

We investigate the nature of ordinary cosmic vortices in some scalar-tensor extensions of gravity. We find solutions for which the dilaton field condenses inside the vortex core. These solutions can be interpreted as raising the degeneracy between the eigenvalues of the effective stress-energy tensor, namely the energy per unit length U and the tension T, by picking a privileged spacelike or timelike coordinate direction; in the latter case, a phase frequency threshold occurs that is similar to what is found in ordinary neutral current-carrying cosmic strings. We find that the dilaton contribution for the equation of state, once averaged along the string worldsheet, vanishes, leading to an effective Nambu-Goto behavior of such a string network in cosmology, i.e. on very large scales. It is found also that on small scales, the energy per unit length and tension depend on the string internal coordinates in such a way as to permit the existence of centrifugally supported equilibrium configuration, also known as vortons, whose stability, depending on the very short distance (unknown) physics, can lead to catastrophic consequences on the evolution of the Universe.Comment: 10 pages, ReVTeX, 2 figures, minor typos corrected. This version to appear in Phys. Rev.