On the extension of real regular embedding

2008 ◽  
Vol 40 (5) ◽  
pp. 801-806 ◽  
Author(s):  
Zbigniew Jelonek
Keyword(s):  
2018 ◽  
Vol 29 (11) ◽  
pp. 1850073 ◽  
Author(s):  
Naohiko Kasuya ◽  
Masamichi Takase

We show that, for a closed orientable [Formula: see text]-manifold, with [Formula: see text] not congruent to 3 modulo 4, the existence of a CR-regular embedding into complex [Formula: see text]-space ensures the existence of a totally real embedding into complex [Formula: see text]-space. This implies that a closed orientable [Formula: see text]-manifold with non-vanishing Kervaire semi-characteristic possesses no CR-regular embedding into complex [Formula: see text]-space. We also pay special attention to the cases of CR-regular embeddings of spheres and of simply-connected 5-manifolds.


2020 ◽  
Vol 18 (1) ◽  
pp. 1719-1726
Author(s):  
Xue Yu ◽  
Ben Gong Lou

Abstract A map is called edge-regular if it is edge-transitive but not arc-transitive. In this paper, we show that a complete graph K n {K}_{n} has an orientable edge-regular embedding if and only if n = p d > 3 n={p}^{d}\gt 3 with p an odd prime such that p d ≡ 3 {p}^{d}\equiv 3 ( mod 4 ) (\mathrm{mod}\hspace{.25em}4) . Furthermore, K p d {K}_{{p}^{d}} has p d − 3 4 d ϕ ( p d − 1 2 ) \tfrac{{p}^{d}-3}{4d}\hspace{0.25em}\phi \left(\tfrac{{p}^{d}-1}{2}\right) non-isomorphic orientable edge-regular embeddings.


2015 ◽  
Vol 26 (05) ◽  
pp. 1550033 ◽  
Author(s):  
Marko Slapar

We show that a compact orientable 4-manifold M has a CR regular immersion into ℂ3 if and only if both its first Pontryagin class p1(M) and its Euler characteristic χ(M) vanish, and has a CR regular embedding into ℂ3 if and only if in addition the second Stiefel–Whitney class w2(M) vanishes.


1998 ◽  
Vol 130 (3) ◽  
pp. 293-311
Author(s):  
Pierre Antoine Grillet
Keyword(s):  

1989 ◽  
Vol 04 (11) ◽  
pp. 1013-1025 ◽  
Author(s):  
P. FRE’ ◽  
F. GLIOZZI ◽  
A. PIRAS

It is pointed out that in the Kac-Moody algebras fulfilling the fermionization criterion of Goddard, Nahm and Olive and having a non-minimal value of the central charge k, only a proper subset of the allowed unitary highest weight representations can actually be encoded in a free fermion theory. These truly fermionizable representations are selected by a very specific non-regular embedding of the fermionizable Kac-Moody algebra into the lowest level SO (N F ) Kac-Moody algebra, N F being both the number of fermions and the dimension of the GNO symmetric space. This embedding is a particular case of the embeddings considered by Bais and Bouwknegt and by Schellekens and Warner, for which the Virasoro central charge of the subgroup is equal to that of the group. Furthermore, these fermionizable representations span an orbit of the modular group always leading to a non trivial modular invariant partition function.


2008 ◽  
Vol 98 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Gareth Jones ◽  
Roman Nedela ◽  
Martin Škoviera

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