U.S. DOE carbon capture program: Advancing multiple generations of carbon capture solutions laboratory to pilot scale development

The changing energy profile of the United States has reduced energy-related carbon dioxide emissions, according to the DOE Energy Information Administration (EIA). However, this does not preclude the need for carbon capture, utilization and storage (CCUS) as an important solution to climate change. In fact, the change only further supports the need to develop flexible and cost effective carbon capture technologies that can be applied to various fuel sources for power generation application. CCUS is one of many approaches but is critical to significantly reducing domestic and global CO2 emissions, considering CO2 atmospheric concentrations reached 400 ppm in May 2013 according to the Mauna Loa Atmospheric Observatory. IEA’s 2015 Energy Technology Perspectives indicates that “CCS is the only means for dramatically reduce emission intensity from many industrial processes…”[1]. In addition, the UN IPCC further defined its importance by stating that the absence of CCS will increase the CO2 mitigation cost by 138%[2]. However, the energy and capital cost for state-of-the-art carbon capture systems are prohibitive for any meaningful deployment. In order to address these issues, the Department of Energy’s Carbon Capture Program has worked with researchers to develop, verify the performance and cost benefits of their concepts, and field test promising advanced capture technologies. This presentation will discuss the breadth of the Department of Energy’s Carbon Capture Program, the latest status of its pilot-scale capture technologies within the Program, discuss some lessons learned and its steps toward supporting the next “Transformational” generation of carbon capture technologies

Dynamic Credit Investment in Partially Observed Markets

We consider the problem of maximizing expected utility for a power investor who can allocate his wealth in a stock, a defaultable security, and a money market account. The dynamics of these security prices are governed by geometric Brownian motions modulated by a hidden continuous time finite state Markov chain. We reduce the partially observed stochastic control problem to a complete observation risk sensitive control problem via the filtered regime switching probabilities. We separate the latter into pre-default and post-default dynamic optimization subproblems, and obtain two coupled Hamilton-Jacobi-Bellman (HJB) partial differential equations. We prove existence and uniqueness of a globally bounded classical solution to each HJB equation, and give the corresponding verification theorem. We provide a numerical analysis showing that the investor increases his holdings in stock as the filter probability of being in high growth regimes increases, and decreases his credit risk exposure when the filter probability of being in high default risk regimes gets larger

Scalar field quasinormal modes on asymptotically locally flat rotating black holes in three dimensions

The pure quadratic term of New Massive Gravity in three dimensions admits asymptotically locally flat, rotating black holes. These black holes are characterized by their mass and angular momentum, as well as by a hair of gravitational origin. As in the Myers-Perry solution in dimensions greater than five, there is no upper bound on the angular momentum. We show that, remarkably, the equation for a massless scalar field on this background can be solved in an analytic manner and that the quasinormal frequencies can be found in a closed form. The spectrum is obtained requiring ingoing boundary conditions at the horizon and an asymptotic behavior at spatial infinity that provides a well-defined action principle for the scalar probe. As the angular momentum of the black hole approaches zero, the imaginary part of the quasinormal frequencies tends to minus infinity, migrating to the north pole of the Riemann Sphere and providing infinitely damped modes of high frequency. We show that this is consistent with the fact that the static black hole within this family does not admit quasinormal modes for a massless scalar probe.Comment: 17 pages, 5 figures. V2: improved figures. V3: typos corrected, references added and title slightly changed to match the version to appear in EPJ

Kinematical Lie algebras via deformation theory

We present a deformation theory approach to the classification of kinematical Lie algebras in 3+1 dimensions and present calculations leading to the classifications of all deformations of the static kinematical Lie algebra and of its universal central extension, up to isomorphism. In addition we determine which of these Lie algebras admit an invariant symmetric inner product. Among the new results, we find some deformations of the centrally extended static kinematical Lie algebra which are extensions (but not central) of deformations of the static kinematical Lie algebra. This paper lays the groundwork for two companion papers which present similar classifications in dimension D + 1 for all D>3 and in dimension 2+1.Comment: 23 pages (v3: final version to appear in Journal of Mathematical Physics

Penrose limits and maximal supersymmetry

We show that the maximally supersymmetric pp-waves of IIB superstring and M-theories can be obtained as a Penrose limit of the supersymmetric AdS x S solutions. In addition we find that in a certain large tension limit, the geometry seen by a brane probe in an AdS x S background is either Minkowski space or a maximally supersymmetric pp-wave.Comment: 12 pages, v2: references adde

Higher-dimensional kinematical Lie algebras via deformation theory

We classify kinematical Lie algebras in dimension $D \geq 4$. This is approached via the classification of deformations of the relevant static kinematical Lie algebra. We also classify the deformations of the universal central extension of the static kinematical Lie algebra in dimension $D\geq 4$. In addition we determine which of these Lie algebras admit an invariant inner product.Comment: 18 pages. (v3:final version to appear in Journal of Mathematical Physics). arXiv admin note: text overlap with arXiv:1711.0611