scholarly journals Effective Action from M-Theory on Twisted Connected Sum G 2-Manifolds

2017 ◽  
Vol 359 (2) ◽  
pp. 535-601 ◽  
Author(s):  
Thaisa C. da C. Guio ◽  
Hans Jockers ◽  
Albrecht Klemm ◽  
Hung-Yu Yeh
1999 ◽  
Vol 14 (26) ◽  
pp. 4121-4142 ◽  
Author(s):  
H. LÜ ◽  
S. MUKHERJI ◽  
C. N. POPE

We study the relationship between static p-brane solitons and cosmological solutions of string theory or M theory. We discuss two different ways in which extremal p-branes can be generalized to nonextremal ones, and show how wide classes of recently discussed cosmological models can be mapped into nonextremal p-brane solutions of one of these two kinds. We also extend previous discussions of cosmological solutions to include some that make use of cosmological-type terms in the effective action that can arise from the generalized dimensional reduction of string theory or M theory.


2001 ◽  
Vol 508 (1-2) ◽  
pp. 155-167 ◽  
Author(s):  
S.James Gates ◽  
Hitoshi Nishino
Keyword(s):  

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Andreas P. Braun

Abstract We construct the M-Theory lifts of type IIA orientifolds based on K3-fibred Calabi-Yau threefolds with compatible involutions. Such orientifolds are shown to lift to M-Theory on twisted connected sum G2 manifolds. Beautifully, the two building blocks forming the G2 manifold correspond to the open and closed string sectors. As an application, we show how to use such lifts to explicitly study open string moduli. Finally, we use our analysis to construct examples of G2 manifolds with different inequivalent TCS realizations.


2008 ◽  
Vol 2008 ◽  
pp. 1-27 ◽  
Author(s):  
Masao Iihoshi ◽  
Sergei V. Ketov

We review the status of the fourth-order (quartic in the spacetime curvature) terms induced by superstrings/M-theory (compactified on a warped torus) in the leading order with respect to the Regge slope parameter, and study their (nonperturbative) impact on the evolution of the Hubble scale in the context of the four-dimensional FRW cosmology. After taking into account the quantum ambiguities in the definition of the off-shell superstring effective action, we propose the generalized Friedmann equations, find the existence of their (de Sitter) exact inflationary solutions without a spacetime singularity, and constrain the ambiguities by demanding stability and the scale factor duality invariance of our solutions. The most naive (Bel-Robinson tensor squared) quartic terms are ruled out, thus giving the evidence for the necessity of extra quartic (Ricci tensor-dependent) terms in the off-shell gravitational effective action for superstrings. Our methods are generalizable to the higher orders in the spacetime curvature.


2007 ◽  
Vol 22 (07) ◽  
pp. 1279-1300 ◽  
Author(s):  
IGOR KRIZ ◽  
HAO XING

Diaconescu, Moore and Witten proved that the partition function of type IIA string theory coincides (to the extent checked) with the partition function of M-theory. One of us (Kriz) and Sati proposed in a previous paper a refinement of the IIA partition function using elliptic cohomology and conjectured that it coincides with a partition function coming from F-theory. In this paper, we define the geometric term of the F-theoretical effective action on type IIA compactifications. In the special case when the first Pontrjagin class of space–time vanishes, we also prove a version of the Kriz–Sati conjecture by extending the arguments of Diaconescu–Moore–Witten. We also briefly discuss why even this special case allows interesting examples.


1997 ◽  
Vol 22 (2) ◽  
pp. 103-133 ◽  
Author(s):  
Edward Witten
Keyword(s):  

1998 ◽  
Vol 59 (2) ◽  
Author(s):  
Seungjoon Hyun ◽  
Youngjai Kiem ◽  
Hyeonjoon Shin

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