Results 11 to 20 of about 910 (47)
Complex structures on the complexification of a real Lie algebra
Let g = a+b be a Lie algebra with a direct sum decomposition such that a and b are Lie subalgebras. Then, we can construct an integrable complex structure J̃ on h = ℝ(gℂ) from the decomposition, where ℝ(gℂ) is a real Lie algebra obtained from gℂby the ...
Yamada Takumi
doaj +1 more source
On generalized G2-structures and T-duality [PDF]
This is a short note on generalized G2-structures obtained as a consequence of a T-dual construction given in del Barco et al. (2017). Given classical G2-structure on certain seven dimensional manifolds, either closed or co-closed, we obtain integrable ...
del Barco, Viviana Jorgelina+1 more
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ON A CERTAIN CLASS OF WEINGARTEN SURFACES IN SOL SPACE
In this paper a certain class of Weingarten surfaces in Sol geometry is considered. The theorem that the only non-planar ruled Weingarten surface composed from vertical geodesics are surfaces r(u, v) = (ae, be, v) is proved.
Zlatko Erjavec
semanticscholar +1 more source
Some relations between Hodge numbers and invariant complex structures on compact nilmanifolds
Let N be a simply connected real nilpotent Lie group, n its Lie algebra, and € a lattice in N. If a left-invariant complex structure on N is Γ-rational, then HƏ̄s,t(Γ/N) ≃ HƏ̄s,t(nC) for each s; t.
Yamada Takumi
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A remark on the Bismut-Ricci form on 2-step nilmanifolds [PDF]
In this note we observe that on a 2-step nilpotent Lie group equipped with a left-invariant SKT structure the (1,1)-part of the Bismut-Ricci form is seminegative definite.
Pujia, Mattia, Vezzoni, Luigi
core +3 more sources
Topology and Integrability in Lagrangian Mechanics
This chapter reviews complete integrability in the setting of Lagrangian/Hamiltonian mechanics. It includes the construction of angle-action variables in illustrative examples, along with a proof of the Liouville-Arnol’d theorem.
L. Butler
semanticscholar +1 more source
Ricci-flat and Einstein pseudoriemannian nilmanifolds
This is partly an expository paper, where the authors’ work on pseudoriemannian Einstein metrics on nilpotent Lie groups is reviewed. A new criterion is given for the existence of a diagonal Einstein metric on a nice nilpotent Lie group.
Conti Diego, Rossi Federico A.
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Homogeneous Riemannian Structures on Berger 3-Spheres [PDF]
13 pages.-- MSC2000 codes: 53C30, 53C25.The homogeneous Riemannian structures on the 3-dimensional Berger spheres, their corresponding reductive decompositions and the associated groups of isometries are obtained.
Grosshans, Frank D.+2 more
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ON THE OFFSETS OF RULED SURFACES IN EUCLIDEAN SPACE
In the present paper, we study evolute offsets of a non-developable ruled surface in Euclidean 3-space E and classify the evolute offset with constant Gaussian curvature and constant mean curvature.
D. Yoon
semanticscholar +1 more source
On the smallest Laplace eigenvalue for naturally reductive metrics on compact simple Lie groups [PDF]
Eldredge, Gordina and Saloff-Coste recently conjectured that, for a given compact connected Lie group $G$, there is a positive real number $C$ such that $\lambda_1(G,g)\operatorname{diam}(G,g)^2\leq C$ for all left-invariant metrics $g$ on $G$.
Lauret, Emilio Agustin
core +2 more sources