59 pages, 30 tables. v2: new results added on type IIA mass spectra, discussion on scales and sources corrected, results and conclusions unaffected, references added. v3: minor corrections, published version. v4: discussion on scale separation improved, conclusions unaffected
本文系统研究含规范、度规通量及 O 平面、D 膜的三维 II 型定向形流真空，构建 RSTU 模型并给出稳定的超对称与非超对称 AdS$_3$/Mkw$_3$ 真空及尺度分离示例。
摘要：
我们启动了一项对三维 II 型定向形流通量真空的系统研究，其中包括规范通量和度规通量、O 平面以及 D 膜。我们推导了简单的通量模型（我们将其命名为 RSTU 模型），这些模型可以用三维中具有半最大 \\(\mathcal{N}=8\\) 超对称性的规范超引力来描述。作为景观理论的一个引子，我们给出了超对称和非超对称 AdS$_3$ 与 Mkw$_3$ 真空的多种多参数族。值得注意的是，标量涨落谱中始终不存在负质量，因此所有真空在半最大超引力内都具有微扰稳定性。我们提供了非超对称 IIB 型 AdS$_3$ 通量真空的示例，这些真空具有参数可控的尺度分离，并且其潜在对偶 CFT$_2$ 算符具有整数值的共形维数。我们还结合沼泽地计划讨论了这些结果的意义。
英文摘要：
We initiate a systematic study of type II orientifold flux vacua in three dimensions including gauge and metric fluxes, O-planes and D-branes. We derive simple flux models (we dub them RSTU-models) that admit a description in terms of gauged supergravities with half-maximal $\,\mathcal{N}=8\,$ supersymmetry in three dimensions. As a landscape appetizer, we present various multi-parametric families of supersymmetric and non-supersymmetric AdS$_{3}$ and Mkw$_{3}$ vacua. Remarkably, negative masses turn out to be always absent in the spectrum of scalar fluctuations, thus making all the vacua perturbatively stable within half-maximal supergravity. We provide examples of non-supersymmetric type IIB AdS$_{3}$ flux vacua which feature parametrically-controlled scale separation and come along with integer-valued conformal dimensions of the would-be dual CFT$_{2}$ operators. We also comment on the implications of our results in light of the Swampland Program.
We use the machine learning technique to search the polytope which can result in an orientifold Calabi-Yau hypersurface and the "naive Type IIB string vacua". We show that neural networks can be trained to give a high accuracy for classifying the orientifold property and vacua based on the newly generated orientifold Calabi-Yau database with $h^{1,1}(X) \leq 6$ arXiv:2111.03078. This indicates the orientifold symmetry may already be encoded in the polytope structure. In the end, we try to use the trained neural networks model to go beyond the database and predict the orientifold signal of poly…
We revisit various aspects of AdS$_4$ flux vacua with scale separation in type II supergravity and M-theory. We show that massless IIA allows both weakly and strongly coupled solutions for which the classical orientifold backreaction can be tuned small. This is explicitly verified by computing the backreaction at leading order in perturbation theory. We give evidence that the strongly coupled solutions can be lifted to scale-separated and sourceless (but classically singular) geometries in 11D supergravity.
We derive the 3D N=1 superpotential for the closed string sector of type IIB supergravity on toroidal O5 orientifolds with co-calibrated G2 structure and RR background flux. We find that such compactifications can provide full closed string moduli stabilization on supersymmetric AdS$_3$ vacua, and once we include brane-supersymmetry-breaking we also find indication for the existence of classical 3D de Sitter solutions. The latter however are rather difficult to reconcile with the shape moduli stabilization and flux quantization. We also discuss the possibility of achieving scale separation in …
We study (orientifolded) toric Calabi-Yau singularities in search for D-brane configurations which lead to dynamical supersymmetry breaking at low energy. By exploiting dimer techniques we are able to determine that while most realizations lead to a Coulomb branch instability, a rather specific construction admits a fully stable supersymmetry breaking vacuum. We describe the geometric structure that a singularity should have in order to host such a construction, and present its simplest example, the Octagon.
We study type IIA orientifold compactifications with fluxes that give rise to perturbatively stable, non-supersymmetric AdS$_4$ vacua with D6-brane gauge sectors. Non-perturbative instabilities can be mediated by D8-branes wrapped on the six internal dimensions $X_6$, if they reduce to 4d membranes with a charge $Q$ larger than its tension $T$. The mismatch $Q \neq T$ arises due to i) curvature corrections and ii) the BIon backreaction of D6-branes wrapping 3-cycles of $X_6$. We give a simple expression for the second effect in toroidal orientifolds, and find that only pairs of 3-cycles at SU(…
We discuss flux compactifications of IIA string theory on G2 holonomy spaces with O2/O6-planes to three dimensions and find two classes of solutions: 1) No-scale Minkowski vacua from NSNS 3-form fluxes and RR 4-form fluxes. 2) By adding Romans mass we find AdS$_3$ vacua for which the AdS scale can be decoupled completely from the KK scale while the solution is at tunable weak coupling and large volume. For the AdS$_3$ vacuum we only have a proper 3D description (i.e. smeared orientifold description) of the solution like the 4D analogue of IIA moduli stabilization from fluxes and O6-planes. Thi…
We present a large class of models of D-branes at (orientifold) Calabi-Yau singularities which enjoy dynamical supersymmetry breaking at low energy, by means of either the $SU(5)$ or 3-2 supersymmetry breaking models. Once embedded in a warped throat or, equivalently, in a large $N$ theory, all models display an instability along a Coulomb branch direction towards supersymmetry preserving vacua. Interestingly, the nature of the runaway mechanism is model-independent and has a precise geometrical interpretation. This naturally suggests the properties a Calabi-Yau singularity should have in orde…
Starting from a peculiar orientifold projection proposed long ago by Angelantonj and Cardella, we elaborate on a novel perturbative scenario that involves only D-branes, together with the two types of orientifold planes ${\rm O}_{\pm}$ and anti-orientifold planes $\overline{\rm O}_{\pm}$. We elucidate the microscopic ingredients of such models, connecting them to a novel realization of brane supersymmetry breaking. Depending on the position of the D-branes in the internal space, supersymmetry can be broken at the string scale on branes, or alternatively only at the massive level. The main nove…
In this work we study ten-dimensional solutions to type IIA string theory of the form AdS$_4$ x $X_6$ which contain orientifold planes and preserve N=1 supersymmetry. In particular, we consider solutions which exhibit some key features of the four-dimensional DGKT proposal for compactifications on Calabi-Yau manifolds with fluxes, and in this sense may be considered their ten-dimensional uplifts. We focus on the supersymmetry equations and Bianchi identities, and find solutions to these that are valid at the two-derivative level and at first order in an expansion parameter which is related to …
We consider massive type IIA orientifold compactifications of the form AdS$_4 \times X_6$, where $X_6$ admits a Calabi-Yau metric and is threaded by background fluxes. From a 4d viewpoint, fluxes generate a potential whose vacua have been classified, including one $\mathcal{N}=1$ and three perturbatively stable $\mathcal{N}=0$ branches. We reproduce this result from a 10d viewpoint, by solving the type IIA equations at the same level of detail as previously done for the $\mathcal{N}=1$ branch. All solutions exhibit localised sources and parametric scale separation. We then analyse the non-pert…
We construct global orientifold limits of singular $F$-theory vacua whose associated gauge groups are SO(3), SO(5), SO(6), $F_4$, SU(4), and Spin(7). For each limit we show a universal tadpole relation is satisfied, which is a homological identity whose dimension-zero component encodes the matching of the D3 charge between each $F$-theory compactification and its orientifold limit. While for smooth $F$-theory compactifications which admit global orientifold limits the contribution to the associated universal tadpole relation comes from its Chern class, we show that for all singular $F$-theory …
We study dimensional reductions of M-theory/type II strings down to 6D in the presence of fluxes and spacetime filling branes and orientifold planes of different types. We classify all inequivalent orientifold projections giving rise to $\mathcal{N}=(1,1)$ supergravities in 6D and work out the embedding tensor/fluxes dictionary for each of those. Finally we analyze the set of vacua for the different classes of reductions and find an abundance of "no-scale" type Minkowski vacua, as well as a few novel examples of (A)dS extrema.
In this thesis we explore the vacua structure of type IIA orientifold (CY) compactifications with fluxes, from the 4d and the 10d point of view. We start by reviewing type IIA Calabi-Yau orientifold compactifications with fluxes. We consider RR and NSNS fluxes, and then add (non)-geometric fluxes. We recall how the potential can be written as a bilinear expression and review the main swampland conjectures involving these scenarios. Once the basics have been setted, we perform a systematic search of vacua, using directly the 4d action. We focus first on the case with RR and NSNS fluxes and then…
We present a vast landscape of O3/O7 orientifolds that descends from the famous set of complete intersection Calabi-Yau threefolds (CICY). We give distributions of topological data relevant for phenomenology such as the orientifold-odd Hodge numbers, the D3-tadpole, and multiplicities of O3 and O7-planes. Somewhat surprisingly, almost all of these orientifolds have conifold singularities whose deformation branches are projected out by the orientifolding. However, they can be resolved, so most of the orientifolds actually descend from a much larger and possibly new set of CY threefolds that can…
Multiple Realisations of N=1 Vacua in Six Dimensions
不久前，D=6中N=1真空的例子被构造为在K3曲面上紧化的IIB型弦论的定向折叠。这些模型的有趣特征之一是D5-膜的存在，表现得像小瞬子，以及额外的张量多重态的出现。从杂化弦论的观点来看，这两种现象都是非微扰现象。虽然东方褶皱模型是研究这些非微扰杂化弦现象的自然环境，但探索这种真空是如何在杂化弦论、M理论和F理论中实现的，并考虑它们之间的关系，是有趣和有益的。特别地，我们考虑了在K3 x S^1/Z_2上紧化的M-理论模型，其中在区间上存在五个膜。有一个家庭这样的模型，产生相同的光谱作为一个子家庭的orientifold模型。通过在T^2上进一步紧化到四维，我们将它们与杂化弦谱联系起来。然后，我们使用杂种优势/IIA型对偶推导出存在的Calabi-Yau 3倍，这应该产生原来的六维orientifold谱，如果我们用它们来紧致F-理论。最后，我们详细展示了如何采取这样的F-理论紧化，返回我们的IIB型orientifold模型的限制。
Orientifolds, Brane Coordinates and Special Geometry
本文报道了在D3-D 7-膜和通量的存在下，K3 x T2/Z2定向褶皱上IIB型真空的规范超重力分析。我们讨论了Minkowski真空对应的超对称临界点以及相关的模的固定，发现与以前的分析一致。一个重要的作用是通过选择的辛全纯部分的特殊几何进入计算的标量势。明确给出了相关的周期矩阵N。阐明了特殊几何与膜模的Born-Infeld作用量之间的关系。
Orientifolds of Gepner models without Kähler moduli
Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS（理论物理研究所，巴黎萨克雷大学，法国原子能和替代能源委员会，法国国家科学研究中心）；Institute for Mathematics and Institute for Theoretical Physics Ruprecht-Karls-Universität Heidelberg（数学研究所与理论物理研究所，海德堡大学）
Comments on $SO/Sp$ Gauge Theories from Brane Configurations with an O6 Plane
我们使用M理论的方法，在存在的orientifold O 6平面，以了解某些方面的真空N=1超对称$SO(N_c)/Sp(N_c)$规范理论在四维。通过利用O6 orientifold的一些一般性质，我们重现了以前获得的一些结果与orientifold O4平面时，味群产生的世界体积动力学的D6膜。用半无限D4膜代替D6膜，得到了N=1有质量超对称规范理论真空模空间的旋转曲线的最一般形式.
We describe a method for finding flux vacua of type IIB string theory in which the Gukov-Vafa-Witten superpotential is exponentially small. We present an example with $W_0 \approx 2 \times 10^{-8}$ on an orientifold of a Calabi-Yau hypersurface with $(h^{1,1},h^{2,1})=(2,272)$, at large complex structure and weak string coupling.
Flux vacua in type IIB compactifications on orbifolds: their finiteness and minimal string coupling
Sorbonne Université（索邦大学）；CNRS（法国国家科学研究中心）；High Energy Physics Research Unit, Faculty of Science, Chulalongkorn University（朱拉隆功大学理学院高能物理研究单元）；Dipartimento di Fisica e Astronomia, Università di Bologna（博洛尼亚大学物理与天文学系）；INFN, Sezione di Bologna（意大利国家核物理研究所博洛尼区分部）
