Corruption and MNCs’ entry mode. An empirical econometric study of Portuguese firms investing in PALOPs

Extant literature on FDI entry modes and corruption tend to convey the idea that corruption leads to the choice of low equity, i.e. joint-ventures with local partners, or non-equity modes, namely export and contracting, in order to avoid the contact with corrupt state officials. Recently, however, Demirbag et al. (2010) argument that, despite corruption, linguistic and historical ties between home and host countries guide MNCs to prefer high equity modes (namely, wholly-owned subsidiaries). Focusing on a rather unexplored setting, the African countries, most specifically the PALOP (Países Africanos de Língua Oficial Portuguesa), which includes countries with both very high (Equatorial Guinea, Guinea-Bissau, and Angola), high (Mozambique, São Tome and Principe) and middle (Cape Verde) levels of corruption, and that maintain quite close linguistic and historical ties with Portugal, we aim at testing Dermirbag’s argumentation; in particular, we aim at assessing the extent to which PALOP’s corruption levels influence the entry modes of Portuguese MNCs in these countries.Corruption, Emerging Economies, Entry mode

Analytical and numerical studies of disordered spin-1 Heisenberg chains with aperiodic couplings

We investigate the low-temperature properties of the one-dimensional spin-1 Heisenberg model with geometric fluctuations induced by aperiodic but deterministic coupling distributions, involving two parameters. We focus on two aperiodic sequences, the Fibonacci sequence and the 6-3 sequence. Our goal is to understand how these geometric fluctuations modify the physics of the (gapped) Haldane phase, which corresponds to the ground state of the uniform spin-1 chain. We make use of different adaptations of the strong-disorder renormalization-group (SDRG) scheme of Ma, Dasgupta and Hu, widely employed in the study of random spin chains, supplemented by quantum Monte Carlo and density-matrix renormalization-group numerical calculations, to study the nature of the ground state as the coupling modulation is increased. We find no phase transition for the Fibonacci chain, while we show that the 6-3 chain exhibits a phase transition to a gapless, aperiodicity-dominated phase similar to the one found for the aperiodic spin-1/2 XXZ chain. Contrary to what is verified for random spin-1 chains, we show that different adaptations of the SDRG scheme may lead to different qualitative conclusions about the nature of the ground state in the presence of aperiodic coupling modulations.Comment: Accepted for publication in Physical Review

Strain controlled oxygen vacancy formation and ordering in CaMnO3_3

We use first-principles calculations to investigate the stability of bi-axially strained \textit{Pnma} perovskite CaMnO$_3$ towards the formation of oxygen vacancies. Our motivation is provided by promising indications that novel material properties can be engineered by application of strain through coherent heteroepitaxy in thin films. While it is usually assumed that such epitaxial strain is accommodated primarily by changes in intrinsic lattice constants, point defect formation is also a likely strain relaxation mechanism. This is particularly true at the large strain magnitudes ($>$4%) which first-principles calculations often suggest are required to induce new functionalities. We find a strong dependence of oxygen vacancy defect formation energy on strain, with tensile strain lowering the formation energy consistent with the increasing molar volume with increasing oxygen deficiency. In addition, we find that strain differentiates the formation energy for different lattice sites, suggesting its use as a route to engineering vacancy ordering in epitaxial thin films.Comment: 7 pages, 7 figure

Spontaneous and Stimulated Raman Scattering near Metal Nanostructures in the Ultrafast, High-Intensity regime

The inclusion of atomic inversion in Raman scattering can significantly alter field dynamics in plasmonic settings. Our calculations show that large local fields and femtosecond pulses combine to yield: (i) population inversion within hot spots; (ii) gain saturation; and (iii) conversion efficiencies characterized by a switch-like transition to the stimulated regime that spans twelve orders of magnitude. While in Raman scattering atomic inversion is usually neglected, we demonstrate that in some circumstances full accounting of the dynamics of the Bloch vector is required

Perturbations in the relaxation mechanism for a large cosmological constant

Recently, a mechanism for relaxing a large cosmological constant (CC) has been proposed [arxiv:0902.2215], which permits solutions with low Hubble rates at late times without fine-tuning. The setup is implemented in the LXCDM framework, and we found a reasonable cosmological background evolution similar to the LCDM model with a fine-tuned CC. In this work we analyse analytically the perturbations in this relaxation model, and we show that their evolution is also similar to the LCDM model, especially in the matter era. Some tracking properties of the vacuum energy are discussed, too.Comment: 18 pages, LaTeX; discussion improved, accepted by CQ

The Chess Players

Originally conducted primarily as a game of war and strategy, chess has evolved to reflect historical developments in Western civilization as well as inspired literary and artistic endeavors in such a fashion as to provide comment, often as metaphor, on the human condition and our place in a cosmos influenced as frequently by chance as by order. The evolution of the game itself, particularly the promotion of a weak and relatively unimportant piece to the most powerful, at a time when a similar shift was taking place in the real world, ensured its survival as it served as an educational tool, an entertainment, and a method for developing military strategy. At the same time, chess has provided inspiration for writers, artists, and filmmakers, whether on the sidelines or as part of the general composition, or providing more substantial thematic and/or metaphorical material. Finally, it is a reflection of humanity’s place in the cosmos altogether. The constantly shifting balance between order and chaos, and its effect on the human condition, is perpetually subject to randomness, introducing choice into the equation: a choice between options which may lead to chaos or order depending on the human element. The Chess Players is a novel-in-stories which are connected by themes involving the role of the queen in chess; tradition—both in a family context and on a larger, social scale; the significance of random chance, giving imagination and intuition the opportunity to take advantage of it; and a tinge of feminism: Irina Orzeł, arriving in a café on an early spring day, with its intimation of something new pending in the air, brings a sea-change to the denizens of an all-male chess club while undergoing a transformation of sorts of her own. The accompanying collection of essays, “A Game For All Reasons: Musings on the Interdisciplinary Nature of Chess,” discusses the evolution of the modern chess queen; Geoffrey Chaucer’s use of chess and fortune in the Book of the Duchess and the Knight’s Tale; and the influence of chess on modernist Marcel Duchamp, who incorporated improvisation and chance into his idiosyncratic fusion of chess-as-art, and surrealist Samuel Bak, whose Jewish heritage and views on war and the human condition inform his paintings, using chess to portray both the devastation of the former and his hope for the latter