Projective geometry of Sasaki-Einstein structures and their compactification

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F19%3A00114700" target="_blank" >RIV/00216224:14310/19:00114700 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.impan.pl/en/publishing-house/journals-and-series/dissertationes-mathematicae/online/113324/projective-geometry-of-sasaki-einstein-structures-and-their-compactification" target="_blank" >https://www.impan.pl/en/publishing-house/journals-and-series/dissertationes-mathematicae/online/113324/projective-geometry-of-sasaki-einstein-structures-and-their-compactification</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4064/dm786-7-2019" target="_blank" >10.4064/dm786-7-2019</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Projective geometry of Sasaki-Einstein structures and their compactification

Popis výsledku v původním jazyce

We show that the standard definitions of Sasaki structures have elegant and simplifying interpretations in terms of projective differential geometry. For Sasaki-Einstein structures we use projective geometry to provide a resolution of such structures into geometrically less rigid components; the latter elemental components are separately, complex, orthogonal, and symplectic holonomy reductions of the canonical projective tractor/Cartan connection. This leads to a characterisation of Sasaki-Einstein structures as projective structures with certain unitary holonomy reductions. As an immediate application, this is used to describe the projective compactification of indefinite (suitably) complete noncompact Sasaki-Einstein structures and to prove that the boundary at infinity is a Fefferman conformal manifold that thus fibres over a nondegenerate CR manifold (of hypersurface type). We prove that this CR manifold coincides with the boundary at infinity for the c-projective compactification of the Kahler-Einstein manifold that arises, in the usual way, as a leaf space for the defining Killing field of the given Sasaki-Einstein manifold. A procedure for constructing examples is given. The discussion of symplectic holonomy reductions of projective structures leads us moreover to a new and simplifying approach to contact projective geometry. This is of independent interest and is treated in some detail.

Název v anglickém jazyce

Projective geometry of Sasaki-Einstein structures and their compactification

Popis výsledku anglicky

We show that the standard definitions of Sasaki structures have elegant and simplifying interpretations in terms of projective differential geometry. For Sasaki-Einstein structures we use projective geometry to provide a resolution of such structures into geometrically less rigid components; the latter elemental components are separately, complex, orthogonal, and symplectic holonomy reductions of the canonical projective tractor/Cartan connection. This leads to a characterisation of Sasaki-Einstein structures as projective structures with certain unitary holonomy reductions. As an immediate application, this is used to describe the projective compactification of indefinite (suitably) complete noncompact Sasaki-Einstein structures and to prove that the boundary at infinity is a Fefferman conformal manifold that thus fibres over a nondegenerate CR manifold (of hypersurface type). We prove that this CR manifold coincides with the boundary at infinity for the c-projective compactification of the Kahler-Einstein manifold that arises, in the usual way, as a leaf space for the defining Killing field of the given Sasaki-Einstein manifold. A procedure for constructing examples is given. The discussion of symplectic holonomy reductions of projective structures leads us moreover to a new and simplifying approach to contact projective geometry. This is of independent interest and is treated in some detail.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10101 - Pure mathematics

Projekt

<a href="/cs/project/GBP201%2F12%2FG028" target="_blank" >GBP201/12/G028: Ústav Eduarda Čecha pro algebru, geometrii a matematickou fyziku</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Dissertationes Mathematicae

ISSN

0012-3862

e-ISSN

1730-6310

Svazek periodika

546

Číslo periodika v rámci svazku

2019

Stát vydavatele periodika

PL - Polská republika

Počet stran výsledku

64

Strana od-do

1-64

Kód UT WoS článku

000559966700001

EID výsledku v databázi Scopus

2-s2.0-85078587080