Centrally extended symmetry algebra of asymptotically Goedel spacetimes

We define an asymptotic symmetry algebra for three-dimensional Goedel spacetimes supported by a gauge field which turns out to be the semi-direct sum of the diffeomorphisms on the circle with two loop algebras. A class of fields admitting this asymptotic symmetry algebra and leading to well-defined conserved charges is found. The covariant Poisson bracket of the conserved charges is then shown to be centrally extended to the semi-direct sum of a Virasoro algebra and two affine algebras.Comment: 12 pages, sign mistake corrected in the central charge, takes precedence over published versio

Kerr/CFT Correspondence in the Low Energy Limit of Heterotic String Theory

We investigate the recently proposed Kerr/CFT correspondence in the context of heterotic string theory. The Kerr/CFT correspondence states that the near-horizon states of an extremal four (or higher) dimensional black hole could be identified with a certain chiral conformal field theory under the conjecture that the central charges from the non-gravitational fields vanish. The corresponding Virasoro algebra is generated by a class of diffeomorphisms which preserves the appropriate boundary conditions on the near-horizon geometry. To understand the chiral conformal field theory, we consider the class of extremal Kerr-Sen black hole (that contains three non-gravitational fields) as a class of solutions in the low energy limit (effective field theory) of heterotic string theory. We derive the expression of the conserved charges for the extremal Kerr-Sen solutions that contain dilaton, abelian gauge filed and antisymmetric tensor filed. We confirm and extend the validity of the conjecture (that the central charges from the non-gravitational fields vanish) for theories including antisymmetric tensor fields. We combine the calculated central charges with the expected form of the temperature using the Cardy formula to obtain the entropy of the extremal black hole microscopically; in agreement with the macroscopic Bekenstein-Hawking entropy of the extremal black hole.Comment: 14 pages, a few sentences added to the introduction, version to appear in JHE

Investigating the Role of LIN-35 and the DREAM Complex in Preserving Fertility Under Stress in C. elegans

Organisms are subjected to environments that can fluctuate and cause them stress. Therefore, organisms must have the ability to adapt to the stress to survive and propagate. Temperature stress is becoming an increasingly relevant type of stress due to climate change and is known to affect fertility in many types of organisms including the model organism Caenorhabditis elegans. Here we examine the role of LIN-35, the single C. elegans homolog of the tumor suppressor Retinoblastoma (pRB), in fertility under moderate temperature stress. We found that lin-35 mutants lose fertility more drastically under moderate temperature stress than wildtype worms, and that this loss of fertility is dependent on both somatic and germline expression of LIN-35. A common cellular response to stress is programmed cell death via apoptosis. In C. elegans, the only adult tissue that exhibits apoptosis is the germline and while germline apoptosis eliminates ~50% of all oogenic germ cell nuclei during normal oogenesis, the induction of higher levels of germline apoptosis appears to be a general response to stressful conditions. LIN-35 was previously shown to be important for germline apoptosis but because it cannot bind to DNA by itself it must work with other partners to regulate genes. A group of proteins LIN-35 works with in some contexts is the DREAM complex, a conserved multi-subunit transcriptional repressor complex. We found that there is an induction of germline apoptosis under moderate temperature stress and that LIN-35 and the DREAM complex are important for this induction. The DREAM complex and LIN-35 are also important for DNA damage induced apoptosis. Together this indicates a general role for LIN-35 and the DREAM complex in the induction of germline apoptosis in response to stress. This role in germline apoptosis may be the role in the germline that LIN-35 has that helps it to preserve fertility

The Relationships Between Nursing Staff Knowledge of Personhood and Resident Cognitive Status

The purpose of this pilot study was to explore the relationships between nursing staff knowledge of extended care resident personhood and resident cognitive status. Eighty nursing staff from two similar extended care facilities in Arkansas completed a self-administered questionnaire to assess their knowledge of 21 residents, including information related to residents’ past jobs/careers; likes/dislikes/ interests; family members; other non-specific knowledge; and total knowledge. The Brief Interview for Mental Status (BIMS) was used to evaluate resident cognitive impairment. Results of a Pearson correlation demonstrate a positive correlation between (1) staff knowledge of residents’ families, and (2) total knowledge of residents with resident cognitive status. Findings suggest that nursing staff utilize creative interventions and exert intentional efforts to obtain resident information to preserve personhood and provide PCDC

Cargese Lectures on the Kerr/CFT Correspondence

We give a short introduction, beginning with the Kerr geometry itself, to the basic results, motivation, open problems and future directions of the Kerr/CFT correspondence.Comment: Lectures given by A. Strominger at Cargese 2010. References update

Hidden Conformal Symmetry of Warped AdS_3 Black Holes

We show that for a certain low frequency limit the wave equation of a generic massive scalar field in the background of the spacelike warped AdS_3 black hole can be written as the Casimir of an SL(2,R) symmetry. Two sets of SL(2,R) generators are found which uncover the hidden SL(2,R)\times SL(2,R) symmetry of the solution. This symmetry is only locally defined and is spontaneously broken to U(1)\times U(1) by a periodic identification of the \phi coordinate. By using the generator of the identification we read the left and right temperatures (T_L,T_R) of the proposed dual conformal field theory which are in complete agreement with the WAdS/CFT conjecture. Moreover, under the above condition of the scalar wave frequency, absorption cross section of the scalar field is consistent with the two-point function of the dual CFT.Comment: 12 pages; V2: references added, minor correction; V3: published version, minor clarification in section 3, typos corrected, one reference adde

Topologically Massive Gravity and Ricci-Cotton Flow

We consider Topologically Massive Gravity (TMG), which is three dimensional general relativity with a cosmological constant and a gravitational Chern-Simons term. When the cosmological constant is negative the theory has two potential vacuum solutions: Anti-de Sitter space and Warped Anti-de Sitter space. The theory also contains a massive graviton state which renders these solutions unstable for certain values of the parameters and boundary conditions. We study the decay of these solutions due to the condensation of the massive graviton mode using Ricci-Cotton flow, which is the appropriate generalization of Ricci flow to TMG. When the Chern-Simons coupling is small the AdS solution flows to warped AdS by the condensation of the massive graviton mode. When the coupling is large the situation is reversed, and warped AdS flows to AdS. Minisuperspace models are constructed where these flows are studied explicitly