The ground state and the long-time evolution in the CMC Einstein flow

Let (g,K)(k) be a CMC (vacuum) Einstein flow over a compact three-manifold M with non-positive Yamabe invariant (Y(M)). As noted by Fischer and Moncrief, the reduced volume V(k)=(-k/3)^{3}Vol_{g(k)}(M) is monotonically decreasing in the expanding direction and bounded below by V_{\inf}=(-1/6)Y(M))^{3/2}. Inspired by this fact we define the ground state of the manifold M as "the limit" of any sequence of CMC states {(g_{i},K_{i})} satisfying: i. k_{i}=-3, ii. V_{i} --> V_{inf}, iii. Q_{0}((g_{i},K_{i}))< L where Q_{0} is the Bel-Robinson energy and L is any arbitrary positive constant. We prove that (as a geometric state) the ground state is equivalent to the Thurston geometrization of M. Ground states classify naturally into three types. We provide examples for each class, including a new ground state (the Double Cusp) that we analyze in detail. Finally consider a long time and cosmologically normalized flow (\g,\K)(s)=((-k/3)^{2}g,(-k/3))K) where s=-ln(-k) is in [a,\infty). We prove that if E_{1}=E_{1}((\g,\K))< L (where E_{1}=Q_{0}+Q_{1}, is the sum of the zero and first order Bel-Robinson energies) the flow (\g,\K)(s) persistently geometrizes the three-manifold M and the geometrization is the ground state if V --> V_{inf}.Comment: 40 pages. This article is an improved version of the second part of the First Version of arXiv:0705.307

Efficient Coordination in Weakest-Link Games

Existing experimental research on behavior in weakest-link games shows overwhelmingly the inability of people to coordinate on the efficient equilibrium, especially in larger groups. We hypothesize that people are able to coordinate on efficient outcomes, provided they have sufficient freedom to choose their interaction neighborhood. We conduct experiments with medium sized and large groups and show that neighborhood choice indeed leads to coordination on the fully efficient equilibrium, irrespective if group size. This leads to substantial welfare effects. Achieved welfare is between 40 and 60 percent higher in games with neighborhood choice than without neighborhood choice. We identify exclusion as the simple but very effective mechanism underlying this result. In early rounds, high performers exclude low performers who in consequence 'learn' to become high performers.efficient coordination, weakest-link, minimum effort, neighborhood choice, experiment

Efficient Coordination in Weakest-Link Games

Existing experimental research on behavior in weakest-link games shows overwhelmingly theinability of people to coordinate on the efficient equilibrium, especially in larger groups. Wehypothesize that people will be able to coordinate on efficient outcomes, provided they havesufficient freedom to choose their interaction neighborhood. We conduct experiments with mediumsized and large groups and show that neighborhood choice indeed leads to coordination on the fullyefficient equilibrium, irrespective of group size. This leads to substantial welfare effects.Achieved welfare is between 40 and 60 percent higher in games with neighborhood choice thanwithout neighborhood choice. We identify exclusion as the simple but very effective mechanismunderlying this result. In early rounds, high performers exclude low performers who in consequence‘learn’ to become high performers.microeconomics ;

Symbolic Processes in ERP versus Legacy System Support

Being hailed as possessing the ability to “drive effective business reengineering and management of core and support processes”, it is not surprising that Enterprise Resource Planning (ERP) systems have been adopted by more than 60% of Fortune 500 companies as at the turn of the century. In contrast, negative connotations have been commonly known to be attached to legacy systems and inhouse developed systems. But yet, some of these legacy systems are not replaced when companies adopt ERP solutions while in-house systems still continue to be developed. This research employs symbolic interactionism as the informing theoretical perspective in an ethnography study of a large government authority in Singapore. Our findings surprisingly indicate that the IS professionals supporting the systems tend to attach rather negative symbols to their SAP system, while viewing their legacy system and in-house software development work in a more favorable light. In this paper, we first describe the different symbolism that has been attached over the years to the ERP vis-à-vis legacy system. We then highlight how certain of the early symbols gradually got sedimented over time, while others did not exhibit similar permanence and presence. As a result of such symbolic realities, we demonstrate the consequent differences in attitudes of the staff involved in ERP support vis-à-vis legacy and in-house system support

Cigarette Smoke Suppresses Type I Interferon-Mediated Antiviral Immunity in Lung Fibroblast and Epithelial Cells

The objective of this study was to investigate the impact of cigarette smoke on innate antiviral defense mechanisms; specifically, we examined the effects of cigarette smoke on the induction of type I interferon (IFN). We observed a dose-dependent decrease in the ability of human lung fibroblast and epithelial cells to elicit an antiviral response against a viral double-strand RNA (dsRNA) mimic, polyI:C, in the presence of cigarette smoke-conditioned medium (SCM). Mechanistically, SCM decreases the expression of IFN-stimulated gene 15 (ISG15) and IFN regulatory factor-7 (IRF-7) transcripts and suppresses the nuclear translocation of key transcription factors, nuclear factor-κB (NF-κB) and IRF-3, after polyI:C stimulation. Furthermore, we provide evidence that the intercellular defense strategy against viral infection is also impaired. We observed a decrease in the ability of fibroblasts to elicit an antiviral state in response to IFN-β stimulation. This was associated with decreased nuclear translocation of phosphorylated Stat1 in response to IFN-β treatment. The effects elicited by SCM are reversible and are almost entirely abrogated in the presence of an antioxidant, such as glutathione. Our findings suggest that cigarette smoke affects the immediate-early, inductive, and amplification phases of the type I IFN response

Combinatorial point for higher spin loop models

Integrable loop models associated with higher representations (spin k/2) of U_q(sl(2)) are investigated at the point q=-e^{i\pi/(k+2)}. The ground state eigenvalue and eigenvectors are described. Introducing inhomogeneities into the models allows to derive a sum rule for the ground state entries.Comment: latest version adds some reference

On the asymptotic spectrum of the reduced volume in cosmological solutions of the Einstein equations

Say S is a compact three-manifold with non-positive Yamabe invariant. We prove that in any long time constant mean curvature Einstein flow over S, having bounded C^{\alpha} space-time curvature at the cosmological scale, the reduced volume (-k/3)^{3}Vol(g(k)) (g(k) is the evolving spatial three-metric and k the mean curvature) decays monotonically towards the volume value of the geometrization in which the cosmologically normalized flow decays. In more basic terms, under the given assumptions, there is volume collapse in the regions where the injectivity radius collapses (i.e. tends to zero) in the long time. We conjecture that under the curvature assumption above the Thurston geometrization is the unique global attractor. We validate it in some special cases.Comment: 25 pages, 2 figure