Reconstruction of inhomogeneous metric perturbations and electromagnetic four-potential in Kerr spacetime

We present a procedure that allows the construction of the metric perturbations and electromagnetic four-potential, for gravitational and electromagnetic perturbations produced by sources in Kerr spacetime. This may include, for example, the perturbations produced by a point particle or an extended object moving in orbit around a Kerr black hole. The construction is carried out in the frequency domain. Previously, Chrzanowski derived the vacuum metric perturbations and electromagnetic four-potential by applying a differential operator to a certain potential $\Psi$. Here we construct $\Psi$ for inhomogeneous perturbations, thereby allowing the application of Chrzanowski's method. We address this problem in two stages: First, for vacuum perturbations (i.e. pure gravitational or electromagnetic waves), we construct the potential from the modes of the Weyl scalars $\psi_{0}$ or $\phi_{0}$. Second, for perturbations produced by sources, we express $\Psi$ in terms of the mode functions of the source, i.e. the energy-momentum tensor $T_{\alpha \beta}$ or the electromagnetic current vector $J_{\alpha}$.Comment: 20 pages; few typos corrected and minor modifications made; accepted to Phys. Rev.

Synergy for a Strong Future FY 2008

Lawrence Livermore National Security, LLC is committed to delivering the best combination of scientific research, technology development, business management, and safe, secure operations in support of Lawrence Livermore National Laboratory's critical national security mission. LLNS was formed specifically to manage LLNL for the Department of Energy's National Nuclear Security Administration. LLNS consists of a team of five organizations renowned for their expertise and accomplishments throughout the U.S. nuclear weapons complex and beyond - Bechtel National, University of California, Babcock & Wilcox, Washington Division of URS Corporation, and Battelle. Bechtel is the nation's largest engineering and construction firm and a leader in project management. The University of California is the world's largest public research institution. Babcock & Wilcox and the Washington Division of URS Corporation are top nuclear facilities contractors and between them manage four of DOE's five safest sites. Battelle is a global leader in science and technology development and commercialization. The LLNS Board of Governors provides oversight for the management of the Laboratory and holds the Director and LLNS President responsible for the Laboratory's performance. The Board has seven standing committees that assist in assessing Laboratory performance and monitoring risks and internal controls. Through the Board of Governors, the Laboratory can reach back to LLNS partner organizations to help ensure that it fulfills its national security mission with excellence in scientific research, technology development, business management, and safe, secure operations. LLNS assumed management of LLNL on October 1, 2007. This report highlights LLNS accomplishments in FY2008, its first year as the Laboratory's managing contractor. It is clear that LLNS and the Laboratory have exploited numerous synergies inherent in their relationship - for example, science and engineering, mission and operations, LLNS partners and LLNL directorates - to notable success

Charged black holes: Wave equations for gravitational and electromagnetic perturbations

A pair of wave equations for the electromagnetic and gravitational perturbations of the charged Kerr black hole are derived. The perturbed Einstein-Maxwell equations in a new gauge are employed in the derivation. The wave equations refer to the perturbed Maxwell spinor $\Phi_0$ and to the shear $\sigma$ of a principal null direction of the Weyl curvature. The whole construction rests on the tripod of three distinct derivatives of the first curvature $\kappa$ of a principal null direction.Comment: 12 pages, to appear in Ap.

A Year of Exceptional Achievements FY 2008

2008 highlights: (1) Stockpile Stewardship and Complex Transformation - LLNL achieved scientific breakthroughs that explain some of the key 'unknowns' in nuclear weapons performance and are critical to developing the predictive science needed to ensure the safety, reliability, and security of the U.S. nuclear deterrent without nuclear testing. In addition, the National Ignition Facility (NIF) passed 99 percent completion, an LLNL supercomputer simulation won the 2007 Gordon Bell Prize, and a significant fraction of our inventory of special nuclear material was shipped to other sites in support of complex transformation. (2) National and Global Security - Laboratory researchers delivered insights, technologies, and operational capabilities that are helping to ensure national security and global stability. Of particular note, they developed advanced detection instruments that provide increased speed, accuracy, specificity, and resolution for identifying and characterizing biological, chemical, nuclear, and high-explosive threats. (3) Exceptional Science and Technology - The Laboratory continued its tradition of scientific excellence and technical innovation. LLNL scientists made significant contributions to Nobel Prize-winning work on climate change. LLNL also received three R&D 100 awards and six Nanotech 50 awards, and dozens of Laboratory scientists and engineers were recognized with professional awards. These honors provide valuable confirmation that peers and outside experts recognize the quality of our staff and our work. (4) Enhanced Business and Operations - A major thrust under LLNS is to make the Laboratory more efficient and cost competitive. We achieved roughly $75 million in cost savings for support activities through organizational changes, consolidation of services, improved governance structures and work processes, technology upgrades, and systems shared with Los Alamos National Laboratory. We realized nonlabor cost savings of$23 million. Severe fiscal constraints necessitated a major workforce restructuring and reduction

Perturbative Approach to an orbital evolution around a Supermassive black hole

A charge-free, point particle of infinitesimal mass orbiting a Kerr black hole is known to move along a geodesic. When the particle has a finite mass or charge, it emits radiation which carries away orbital energy and angular momentum, and the orbit deviates from a geodesic. In this paper we assume that the deviation is small and show that the half-advanced minus half-retarded field surprisingly provides the correct radiation reaction force, in a time-averaged sense, and determines the orbit of the particle.Comment: accepted for publication in the Physical Revie

Gauge Problem in the Gravitational Self-Force II. First Post Newtonian Force under Regge-Wheeler Gauge

We discuss the gravitational self-force on a particle in a black hole space-time. For a point particle, the full (bare) self-force diverges. It is known that the metric perturbation induced by a particle can be divided into two parts, the direct part (or the S part) and the tail part (or the R part), in the harmonic gauge, and the regularized self-force is derived from the R part which is regular and satisfies the source-free perturbed Einstein equations. In this paper, we consider a gauge transformation from the harmonic gauge to the Regge-Wheeler gauge in which the full metric perturbation can be calculated, and present a method to derive the regularized self-force for a particle in circular orbit around a Schwarzschild black hole in the Regge-Wheeler gauge. As a first application of this method, we then calculate the self-force to first post-Newtonian order. We find the correction to the total mass of the system due to the presence of the particle is correctly reproduced in the force at the Newtonian order.Comment: Revtex4, 43 pages, no figure. Version to be published in PR

Regularization of the Teukolsky Equation for Rotating Black Holes

We show that the radial Teukolsky equation (in the frequency domain) with sources that extend to infinity has well-behaved solutions. To prove that, we follow Poisson approach to regularize the non-rotating hole, and extend it to the rotating case. To do so we use the Chandrasekhar transformation among the Teukolsky and Regge-Wheeler-like equations, and express the integrals over the source in terms of solutions to the homogeneous Regge-Wheeler-like equation, to finally regularize the resulting integral. We then discuss the applicability of these results.Comment: 14 pages, 1 Table, REVTE

National Strategic Challenges and the Role of Lawrence Livermore National Laboratory

The end of the Cold War was a water-shed event in history--an event that calls for re-evaluation of the basic assumptions and priorities of US national security that have gone essentially unchallenged for nearly 50 years. Central to this re-evaluation are the changing needs for federal Science and Technology (S and T) investment to underpin national and economic security and the role of the Department of Energy (DOE) national laboratories in fulfilling those needs. The three nuclear weapons laboratories-Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL), and Sandia National Laboratory (SNL)-are major constituents of DOE`s national laboratory system. They helped win the Cold War, and will undoubtedly continue to support US security S and T requirements. This paper discusses of the role these three laboratories, and LLNL in particular, can play in supporting the nation`s S and T priorities. The paper also highlights some of the changes that are necessary for the laboratories to effectively support the national S and T and economic competitiveness agenda. These issues are important to DOE and laboratory managers responsible for the development of strategic direction and implementation plans

Ultrarelativistic circular orbits of spinning particles in a Schwarzschild field

Ultrarelativistic circular orbits of spinning particles in a Schwarzschild field described by the Mathisson-Papapetrou equations are considered. The preliminary estimates of the possible synchrotron electromagnetic radiation of highly relativistic protons and electrons on these orbits in the gravitational field of a black hole are presentedComment: 9 page