Petrie conjecture
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* If $\dim M \leq 8$, the statement is true by the work of {{cite|Dejter1976}} and {{cite|James1985}}. | * If $\dim M \leq 8$, the statement is true by the work of {{cite|Dejter1976}} and {{cite|James1985}}. | ||
* According to {{cite|Hattori1978}}, the conjecture is also true if $M$ admits an invariant almost complex structure with the first Chern class $c_1(M) = (n+1)x$. | * According to {{cite|Hattori1978}}, the conjecture is also true if $M$ admits an invariant almost complex structure with the first Chern class $c_1(M) = (n+1)x$. | ||
− | * Other special cases where the Petrie conjecture holds are described by {{cite|Wang1975}}, {{cite| | + | * Other special cases where the Petrie conjecture holds are described by {{cite|Wang1975}}, {{cite|Yoshida1975/76}}, {{cite|Iberkleid1978}}, {{cite|Muslin1978}}, {{cite|Tsukada&Washiyama1979}}, and {{cite|Masuda1981}}. |
* By the work of {{cite|Dessai2002}}, the total Pontrjagin class of $M$ agrees with that of $\CP^n$ if $\dim M \leq 22$ and the action of $S^1$ on $M$ extends to an appropriate action of $Pin(2)$. | * By the work of {{cite|Dessai2002}}, the total Pontrjagin class of $M$ agrees with that of $\CP^n$ if $\dim M \leq 22$ and the action of $S^1$ on $M$ extends to an appropriate action of $Pin(2)$. | ||
* Similarly, the work of {{cite|Dessai&Wilking2004}} confirms the Petrie conjecture under the assumption that $\dim M \leq 8k-4$ and the action of $S^1$ on $M$ extends to a smooth action of $T^k$ for $k \geq 1$. | * Similarly, the work of {{cite|Dessai&Wilking2004}} confirms the Petrie conjecture under the assumption that $\dim M \leq 8k-4$ and the action of $S^1$ on $M$ extends to a smooth action of $T^k$ for $k \geq 1$. |
Revision as of 21:30, 1 December 2010
This page has not been refereed. The information given here might be incomplete or provisional. |
Contents |
1 Problem
Tex syntax error, what constraints does this place on the topology of
Tex syntax errorin general and on the Pontrjagin classes of
Tex syntax errorin particular? What about the case where
Tex syntax erroris homotopy equivalent to ?
In such a context, Petrie restricted his attention to smooth actions of the Lie group , the circle [Petrie1972] (more generally, the torus for [Petrie1973]), and he posed the following conjecture.
Conjecture 1.1 [Petrie1972].
Suppose thatTex syntax erroris a closed smooth -manifold homotopy equivalent to and that acts smoothly and non-trivially on
Tex syntax error. Then the total Pontrjagin class of
Tex syntax erroragrees with that of , i.e., for a generator ,
2 Progress to date
As of November 30, 2010, the Petrie conjecture has not been confirmed in general. However it has been proven in the following special cases.
- Petrie [Petrie1973] has verified his conjecture under the assumption that the action of on
Tex syntax error
extends to a smooth action of the torus . - If , the statement is true by the work of [Dejter1976] and [James1985].
- According to [Hattori1978], the conjecture is also true if
Tex syntax error
admits an invariant almost complex structure with the first Chern class . - Other special cases where the Petrie conjecture holds are described by [Wang1975], [Yoshida1975/76], [Iberkleid1978], [Muslin1978], [Tsukada&Washiyama1979], and [Masuda1981].
- By the work of [Dessai2002], the total Pontrjagin class of
Tex syntax error
agrees with that of if and the action of onTex syntax error
extends to an appropriate action of . - Similarly, the work of [Dessai&Wilking2004] confirms the Petrie conjecture under the assumption that and the action of on
Tex syntax error
extends to a smooth action of for .
3 Further discussion
A symplectic version of the Petrie conjecture is discussed in the article of [Tolman2010].
4 References
- [Dejter1976] I. J. Dejter, Smooth -manifolds in the homotopy type of , Michigan Math. J. 23 (1976), no.1, 83–95. MR0402789 (53 #6603) Zbl 0326.57009
- [Dessai&Wilking2004] A. Dessai and B. Wilking, Torus actions on homotopy complex projective spaces, Math. Z. 247 (2004), no.3, 505–511. MR2114425 (2006c:57033) Zbl 1068.57034
- [Dessai2002] A. Dessai, Homotopy complex projective spaces with -action, Topology Appl. 122 (2002), no.3, 487–499. MR1911696 (2003f:58048) Zbl 0998.57048
- [Hattori1978] A. Hattori, -structures and -actions, Invent. Math. 48 (1978), no.1, 7–31. MR508087 (80e:57051) Zbl 0395.57020
- [Iberkleid1978] W. Iberkleid, Pseudolinear spheres, Michigan Math. J. 25 (1978), no.3, 359–370. MR512906 (80d:57023) Zbl 0377.57008
- [James1985] D. M. James, Smooth actions on homotopy 's, Michigan Math. J. 32 (1985), no.3, 259–266. MR803831 (87c:57031) Zbl 0602.57026
- [Masuda1981] M. Masuda, On smooth -actions on cohomology complex projective spaces. The case where the fixed point set consists of four connected components, J. Fac. Sci. Univ. Tokyo Sect. IA Math. 28 (1981), no.1, 127–167. MR617869 (82i:57031) Zbl 0462.57019
- [Muslin1978] Template:Muslin1978
- [Petrie1972] T. Petrie, Smooth -actions on homotopy complex projective spaces and related topics, Bull. Amer. Math. Soc. 78 (1972), 105–153. MR0296970 Zbl 0247.57010
- [Petrie1973] T. Petrie, Torus actions on homotopy complex projective spaces, Invent. Math. 20 (1973), 139–146. MR0322893 (48 #1254) Zbl 0262.57021
- [Tolman2010] S. Tolman, On a symplectic generalization of Petrie's conjecture, Trans. Amer. Math. Soc. 362 (2010), no.8, 3963–3996. MR2638879 Zbl 1216.53074
- [Tsukada&Washiyama1979] E. Tsukada and R. Washiyama, -actions on cohomology complex projective spaces with three components of the fixed point sets, Hiroshima Math. J. 9 (1979), no.1, 41–46. MR529325 (80j:57043) Zbl 0411.57037
- [Wang1975] K. Wang, Differentiable circle group actions on homotopy complex projective spaces, Math. Ann. 214 (1975), 73–80. MR0372895 (51 #9099) Zbl 0285.57025
- [Yoshida1975/76] T. Yoshida, On smooth semifree actions on cohomology complex projective spaces, Publ. Res. Inst. Math. Sci. 11 (1975/76), no.2, 483–496. MR0445528 (56 #3868) Zbl 0326.57008
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