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Negative Ricci curvature on some non-solvable Lie groups
(Springer, 2017-02)
We show that for any non-trivial representation (V, π) of u(2) with the center acting as multiples of the identity, the semidirect product u(2) ⋉ πV admits a metric with negative Ricci curvature that can be explicitly ...
Q curvature and gravity
(American Physical Society, 2018-11)
In this paper, we consider a family of n-dimensional, higher-curvature theories of gravity whose action is given by a series of dimensionally extended conformal invariants. The latter correspond to higher-order generalizations ...
Dynamic reduced model and stochastic aspects for PFGM curved beams with variable curvature
(Pergamon-Elsevier Science Ltd, 2021-01)
In this paper a new 1D finite element model for dynamic calculations of PGFM curved beams with variable curvature is developed. The reduced high-speed calculation model allows stochastic aspects in the dynamic of the ...
Curvature flows for almost-hermitian Lie groups
(American Mathematical Society, 2014-12)
We study curvature flows in the locally homogeneous case (e.g. compact quotients of Lie groups, solvmanifolds, nilmanifolds) in a unified way, by considering a generic flow under just a few natural conditions on the broad ...
Non-solvable Lie groups with negative Ricci curvature
(Birkhauser Boston Inc, 2020-06-16)
Until a couple of years ago, the only known examples of Lie groups admitting left-invariant metrics with negative Ricci curvature were either solvable or semisimple.We use a general construction from a previous article of ...
Evaluation of the curvature ductility ratio of a circular cross-section of concrete reinforced with GFRP bars
(Institute of Physics Publishing, 2020-02-28)
The present study deals with the use of fiberglass reinforced polymer bars (GFRP) as a replacement for the common steel of a reinforced concrete circular pile, in order to avoid the corrosion of durability of reinforcing ...
Negative Ricci curvature on some non-solvable Lie groups II
(Springer, 2020-04)
We construct many examples of Lie groups admitting a left-invariant metric of negative Ricci curvature. We study Lie algebras which are semidirect products l= (a⊕ u) ⋉ n and we obtain examples where u is any semisimple ...
Sectional curvature and commutation of pairs of selfadjoint operators
(Theta Foundation, 2006-04)
The space G^+ of postive invertible operators of a C*-algebra A, with the appropriate Finsler metric, behaves like a (non positively curved)symmetric space. Among the characteristic properties of such spaces, one has that ...
A free boundary problem in Orlicz spaces related to mean curvature
(Elsevier, 2021-11)
In this paper we address a one phase minimization problem for a functional that includes the perimeter of the positivity set. It also includes three terms, the first one is ∫fu and the second ∫u>0h where f and h are bounded ...