Entropy as a function of Geometric Phase

We give a closed-form solution of von Neumann entropy as a function of geometric phase modulated by visibility and average distinguishability in Hilbert spaces of two and three dimensions. We show that the same type of dependence also exists in higher dimensions. We also outline a method for measuring both the entropy and the phase experimentally using a simple Mach-Zehnder type interferometer which explains physically why the two concepts are related.Comment: 19 pages, 7 figure

Setting up tunneling conditions by means of Bohmian mechanics

Usually tunneling is established after imposing some matching conditions on the (time-independent) wave function and its first derivative at the boundaries of a barrier. Here an alternative scheme is proposed to determine tunneling and estimate transmission probabilities in time-dependent problems, which takes advantage of the trajectory picture provided by Bohmian mechanics. From this theory a general functional expression for the transmission probability in terms of the system initial state can be reached. This expression is used here to analyze tunneling properties and estimate transmissions in the case of initial Gaussian wave packets colliding with ramp-like barriers.Comment: 18 pages, 4 figure

Causality in AdS/CFT and Lovelock theory

We explore the constraints imposed on higher curvature corrections of the Lovelock type due to causality restrictions in the boundary of asymptotically AdS space-time. In the framework of AdS/CFT, this is related to positivity of the energy constraints that arise in conformal collider physics. We present explicit analytic results that fully address these issues for cubic Lovelock gravity in arbitrary dimensions and give the formal analytic results that comprehend general Lovelock theory. The computations can be performed in two ways, both by considering a thermal setup in a black hole background and by studying the scattering of gravitons with a shock wave in AdS. We show that both computations coincide in Lovelock theory. The different helicities, as expected, provide the boundaries defining the region of allowed couplings. We generalize these results to arbitrary higher dimensions and discuss their consequences on the shear viscosity to energy density ratio of CFT plasmas, the possible existence of Boulware-Deser instabilities in Lovelock theory and the extent to which the AdS/CFT correspondence might be valid for arbitrary dimensions.Comment: 35 pages, 20 figures; v2: minor amendments and clarifications include

Ungentlemanly Capitalism: John Hay and Malaya, 1904-1964

John Hay was one of Britain’s leading colonial capitalists, building his career from the 1900s to the 1960s in Malaya’s plantation industry. He became the leading spokesperson for the British rubber growers, and played a major role in the formulation of international restriction schemes during the 1930s. Hay was a remarkable entrepreneurial talent, consolidating his corporate power through the premiere Malayan agency house, Guthrie & Co. This in itself challenges the notion that Britain’s myriad of ‘free-standing’ companies, which were typical of direct investment in the Empire, represented a relatively weak and unsustainable form of multinational enterprise. But Hay’s dominance of the Malayan plantation sector also questions the notion of ‘gentlemanly capitalism’ as the driving force behind the expansion and sustenance of the British imperial system. Hay’s network of colonial corporate influence did not extend into the corridors of ‘gentlemanly capitalist’ power in Whitehall and the City, where he often had frosty relations. Ultimately, it was the financial sector in London that brought about Hay’s forced resignation from Guthrie in 1963. Examining questions of class, ethnicity, personality, ideology and strategy, the article focuses on why Hay did not develop better relations with commercial, financial and official elites, issues that would also engender tensions with the post-colonial political and business leadership of Malaya/Malaysia

Quantum Corrections for ABGB Black Hole

In this paper, we study quantum corrections to the temperature and entropy of a regular Ay\'{o}n-Beato-Garc\'{\i}a-Bronnikov black hole solution by using tunneling approach beyond semiclassical approximation. We use the first law of black hole thermodynamics as a differential of entropy with two parameters, mass and charge. It is found that the leading order correction to the entropy is of logarithmic form. In the absence of the charge, i.e., $e=0$, these corrections approximate the corresponding corrections for the Schwarzschild black hole.Comment: 15 pages, accepted for publication in Astrophysics and Space Scienc