Recent results in Euclidean dynamical triangulations

We study a formulation of lattice gravity defined via Euclidean dynamical triangulations (EDT). After fine-tuning a non-trivial local measure term we find evidence that four-dimensional, semi-classical geometries are recovered at long distance scales in the continuum limit. Furthermore, we find that the spectral dimension at short distance scales is consistent with 3/2, a value that is also observed in the causal dynamical triangulation (CDT) approach to quantum gravity.Comment: 7 pages, 3 figures. Proceedings for the 3rd conference of the Polish society on relativit

Lattice Quantum Gravity and Asymptotic Safety

We study the nonperturbative formulation of quantum gravity defined via Euclidean dynamical triangulations (EDT) in an attempt to make contact with Weinberg's asymptotic safety scenario. We find that a fine-tuning is necessary in order to recover semiclassical behavior. Such a fine-tuning is generally associated with the breaking of a target symmetry by the lattice regulator; in this case we argue that the target symmetry is the general coordinate invariance of the theory. After introducing and fine-tuning a nontrivial local measure term, we find no barrier to taking a continuum limit, and we find evidence that four-dimensional, semiclassical geometries are recovered at long distance scales in the continuum limit. We also find that the spectral dimension at short distance scales is consistent with 3/2, a value that could resolve the tension between asymptotic safety and the holographic entropy scaling of black holes. We argue that the number of relevant couplings in the continuum theory is one, once symmetry breaking by the lattice regulator is accounted for. Such a theory is maximally predictive, with no adjustable parameters. The cosmological constant in Planck units is the only relevant parameter, which serves to set the lattice scale. The cosmological constant in Planck units is of order 1 in the ultraviolet and undergoes renormalization group running to small values in the infrared. If these findings hold up under further scrutiny, the lattice may provide a nonperturbative definition of a renormalizable quantum field theory of general relativity with no adjustable parameters and a cosmological constant that is naturally small in the infrared.Comment: 69 pages, 25 figures. Revised discussion of target symmetry throughout paper. Numerical results unchanged and main conclusions largely unchanged. Added references and corrected typos. Conforms with version published in Phys. Rev.

Still Soldiers and Scholars? An Analysis of Army Officer Testing

Still Soldiers and Scholars? sheds light on a neglected aspect of talent management, namely, officer accessions testing and evaluation. It does so by tracing the history of officer testing since 1900, identifying and analyzing key developments in the assessment process, and then offering recommendations about how the Army should revise its approach to officer testing. This book supplements a series of monographs written by the Army’s Office of Economic and Manpower Analysis (OEMA) and published by the Strategic Studies Institute (SSI) in 2009 and 2010. In those monographs, the authors proposed an officer corps strategy based on the theory of talent management. This book is a necessary first step in reforming the Army’s officer accessions effort in order to better align it with the Army’s talent-based approach to officer management.https://press.armywarcollege.edu/monographs/1000/thumbnail.jp