Zobrazeno 1 - 8
of 8
pro vyhledávání: '"Barbara De Leo"'
Publikováno v:
Rendiconti di Matematica e delle Sue Applicazioni, Vol 29, Iss 2, Pp 163-173 (2009)
We study the curvature properties of a large class of four-dimensional Walker metrics. Several interesting examples are found, in particular as regards local symmetry, conformal flatness and Einstein-like metrics. Studiamo le proprietà di curvatura
Externí odkaz:
https://doaj.org/article/5b3ff7d7727643b6b9929ac801cad6d0
Publikováno v:
Rendiconti di Matematica e delle Sue Applicazioni, Vol 29, Iss 2, Pp 163-173 (2009)
We study the curvature properties of a large class of four-dimensional Walker metrics. Several interesting examples are found, in particular as regards local symmetry, conformal flatness and Einstein-like metrics. Studiamo le proprietà di curvatura
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::8f9a5c0c7c26fbdba96105798a403931
https://www1.mat.uniroma1.it/ricerca/rendiconti/ARCHIVIO/2009(2)/163-173.pdf
https://www1.mat.uniroma1.it/ricerca/rendiconti/ARCHIVIO/2009(2)/163-173.pdf
Autor:
Barbara De Leo
Publikováno v:
Kyungpook mathematical journal. 52:1-11
Our attention is turned to four-dimensional pseudo-Riemannian naturally reductive homogeneous spaces. In particular, our study leads to a complete classification of them.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::819f729adcdccb150c1b78fe8e4c0e71
https://doi.org/10.5666/kmj.2012.52.1.1
https://doi.org/10.5666/kmj.2012.52.1.1
Autor:
Barbara De Leo, Joeri Van der Veken
Publikováno v:
Geometriae Dedicata. 159:373-387
We prove that a four-dimensional generalized symmetric space does not admit any non-degenerate hypersurfaces with parallel second fundamental form, in particular non-degenerate totally geodesic hypersurfaces, unless it is locally symmetric. However,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::93c6ebf04ffc672455f25b18feebcc18
https://doi.org/10.1007/s10711-011-9665-1
https://doi.org/10.1007/s10711-011-9665-1
Autor:
Barbara De Leo, Giovanni Calvaruso
Publikováno v:
Acta Mathematica Hungarica. 132:269-293
We investigate Ricci solitons on Lorentzian three-manifolds (M,gf) admitting a parallel degenerate line field. For several classes of these manifolds, described in terms of the defining function f, the existence of non-trivial Ricci solitons is prove
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a17dd1e9fb7014524b5fcd1f3e448d5a
https://doi.org/10.1007/s10474-010-0049-z
https://doi.org/10.1007/s10474-010-0049-z
Autor:
Giovanni Calvaruso, Barbara De Leo
We characterize semi-symmetric Lorentzian three-manifolds (M,gf) admitting a parallel degenerate line field, through a condition on the defining function f. The admissible Segre types of the Ricci operator of (M,gf) are also completely described, and
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d51533c5e24209c78d1fa37dd876a139
https://hdl.handle.net/11587/332865
https://hdl.handle.net/11587/332865
The curvature of Lorentzian manifolds (Mn,g), admitting a group of isometries of dimension at least 1/2n(n − 1) + 1, is completely described. Interesting behaviours are found, in particular as concerns local symmetry, local homogeneity and conforma
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0228aa78cab7b5825edc883904bddddd
https://hdl.handle.net/11587/332862
https://hdl.handle.net/11587/332862