52 research outputs found
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.
Variation of mortality after coronary artery bypass surgery in relation to hour, day and month of the procedure
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
Antibody structure and engineering considerations for the design and function of Antibody Drug Conjugates (ADCs)
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