Local free-fall temperature of a RN-AdS black hole

We use the global embedding Minkowski space (GEMS) geometries of a (3+1)-dimensional curved Reissner-Nordstr\"om(RN)-AdS black hole spacetime into a (5+2)-dimensional flat spacetime to define a proper local temperature, which remains finite at the event horizon, for freely falling observers outside a static black hole. Our extended results include the known limiting cases of the RN, Schwarzschild--AdS, and Schwarzschild black holes.Comment: 18 pages, 11 figures, version to appear in Int. J. Mod. Phys.

Holographic Superconductors with Lifshitz Scaling

Black holes in asymptotically Lifshitz spacetime provide a window onto finite temperature effects in strongly coupled Lifshitz models. We add a Maxwell gauge field and charged matter to a recently proposed gravity dual of 2+1 dimensional Lifshitz theory. This gives rise to charged black holes with scalar hair, which correspond to the superconducting phase of holographic superconductors with z > 1 Lifshitz scaling. Along the way we analyze the global geometry of static, asymptotically Lifshitz black holes at arbitrary critical exponent z > 1. In all known exact solutions there is a null curvature singularity in the black hole region, and, by a general argument, the same applies to generic Lifshitz black holes.Comment: 23 pages, 4 figures; v2: added references; v3: matches published versio

Thermodynamics of Large AdS Black Holes

We consider leading order quantum corrections to the geometry of large AdS black holes in a spherical reduction of four-dimensional Einstein gravity with negative cosmological constant. The Hawking temperature grows without bound with increasing black hole mass, yet the semiclassical back-reaction on the geometry is relatively mild, indicating that observers in free fall outside a large AdS black hole never see thermal radiation at the Hawking temperature. The positive specific heat of large AdS black holes is a statement about the dual gauge theory rather than an observable property on the gravity side. Implications for string thermodynamics with an AdS infrared regulator are briefly discussed.Comment: 17 pages, 1 figure, v2. added reference

Thermal Correlators in Holographic Models with Lifshitz scaling

We study finite temperature effects in two distinct holographic models that exhibit Lifshitz scaling, looking to identify model independent features in the dual strong coupling physics. We consider the thermodynamics of black branes and find different low-temperature behavior of the specific heat. Deformation away from criticality leads to non-trivial temperature dependence of correlation functions and we study how the characteristic length scale in the two point function of scalar operators varies as a function of temperature and deformation parameters.Comment: 28 pages, 8 figures; typos corrected, references added, published versio

Ethical governance is essential to building trust in robotics and artificial intelligence systems

© 2018 The Author(s) Published by the Royal Society. All rights reserved. This paper explores the question of ethical governance for robotics and artificial intelligence (AI) systems. We outline a roadmap-which links a number of elements, including ethics, standards, regulation, responsible research and innovation, and public engagement-as a framework to guide ethical governance in robotics and AI. We argue that ethical governance is essential to building public trust in robotics and AI, and conclude by proposing five pillars of good ethical governance. This article is part of the theme issue 'Governing artificial intelligence: ethical, legal, and technical opportunities and challenges'

Black Hole Thermodynamics and Heavy Fermion Metals

Heavy fermion alloys at critical doping typically exhibit non-Fermi-liquid behavior at low temperatures, including a logarithmic or power law rise in the ratio of specific heat to temperature as the temperature is lowered. Anomalous specific heat of this type is also observed in a simple class of gravitational dual models that exhibit anisotropic scaling with dynamical critical exponent z > 1.Comment: 17 pages, 4 figures; v2: added references; v3: matches published versio

Holographic Superconductor for a Lifshitz fixed point

We consider the gravity dual of strongly coupled system at a Lifshitz-fixed point and finite temperature, which was constructed in a recent work arXiv:0909.0263. We construct an Abelian Higgs model in that background and calculate condensation and conductivity using holographic techniques. We find that condensation happens and DC conductivity blows up when temperature turns below a critical value.Comment: 14 pages, 4 figures, v4: improved version, references adde

Complementarities between IT and Organizational Structure: The Role of Corporate Exploration and Exploitation

The decentralization of organizational decision authority has been shown to be complementary to Information Technology (IT) in prior research. We draw from the information processing view of organizations, the IT and de/centralization debate, and organizational learning theory to argue that IT payoffs can also be improved by greater centralization of decision authority, contingent on a firm’s corporate learning type. We argue that an exploratory learning type is best pursued with a decentralized organization design, while an exploitative learning type requires a centralized organization design. We hypothesize that under corporate exploration, IT payoffs are enhanced through greater decentralization, whereas under corporate exploitation, returns to IT are improved by greater centralization. Our study uses a novel multi‐source panel on the IT capital, the degree of de/centralization, and the performance of almost 260 German manufacturing firms. We estimate production functions to assess the contribution of combning IT with de/centralization to firmlevel productivity under different corporate learning types. Our results strongly support our hypotheses and hold up to a variety of robustness tests

Holographic superconductor models in the non-minimal derivative coupling theory

We study a general class of holographic superconductor models via the St\"{u}ckelberg mechanism in the non-minimal derivative coupling theory in which the charged scalar field is kinetically coupling to Einstein's tensor. We explore the effects of the coupling parameter on the critical temperature, the order of phase transitions and the critical exponents near the second-order phase transition point. Moreover, we compute the electric conductive using the probe approximation and check the ratios $\omega_g/T_c$ for the different coupling parameters.Comment: 12 pages, 5 figure