scholarly journals The tadpole problem

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Iosif Bena ◽  
Johan Blåbäck ◽  
Mariana Graña ◽  
Severin Lüst
Keyword(s):  
Moduli Space ◽  
Complex Structure ◽  
De Sitter ◽  
Generic Point ◽  
Cancellation Condition ◽  
Moduli Stabilization ◽  
Induced Charge ◽  
De Sitter Vacua ◽  
Breaking Scale ◽  
Rule Out

Abstract We examine the mechanism of moduli stabilization by fluxes in the limit of a large number of moduli. We conjecture that one cannot stabilize all complex-structure moduli in F-theory at a generic point in moduli space (away from singularities) by fluxes that satisfy the bound imposed by the tadpole cancellation condition. More precisely, while the tadpole bound in the limit of a large number of complex-structure moduli goes like 1/4 of the number of moduli, we conjecture that the amount of charge induced by fluxes stabilizing all moduli grows faster than this, and is therefore larger than the allowed amount. Our conjecture is supported by two examples: K3 × K3 compactifications, where by using evolutionary algorithms we find that moduli stabilization needs fluxes whose induced charge is 44% of the number of moduli, and Type IIB compactifications on $$ \mathbbm{CP} $$ CP 3, where the induced charge of the fluxes needed to stabilize the D7-brane moduli is also 44% of the number of these moduli. Proving our conjecture would rule out de Sitter vacua obtained via antibrane uplift in long warped throats with a hierarchically small supersymmetry breaking scale, which require a large tadpole.

scholarly journals Winding uplifts and the challenges of weak and strong SUSY breaking in AdS

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Arthur Hebecker ◽  
Sascha Leonhardt
Keyword(s):  
Complex Structure ◽  
Susy Breaking ◽  
Technical Level ◽  
De Sitter ◽  
Large Complex ◽  
Breaking Scale ◽  
Large Complex Structure

Abstract We discuss the problem of metastable SUSY breaking in the landscape. While this is clearly crucial for the various de Sitter proposals, it is also interesting to consider the SUSY breaking challenge in the AdS context. For example, it could be that a stronger form of the non-SUSY AdS conjecture holds: it would forbid even metastable non-SUSY AdS in cases where the SUSY-breaking scale is parametrically above/below the AdS scale. At the technical level, the present paper proposes to break SUSY using the multi-cosine-shaped axion potentials which arise if a long winding trajectory of a ‘complex-structure axion’ appears in the large-complex-structure limit of a Calabi-Yau orientifold. This has been studied in the context of ‘Winding Inflation’, but the potential for SUSY breaking has not been fully explored. We discuss the application to uplifting LVS vacua, point out the challenges which one faces in the KKLT context, and consider the possibility of violating the non-SUSY AdS conjecture in the type-IIA setting of DGKT.

scholarly journals Weak gravity bounds in asymptotic string compactifications

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Brice Bastian ◽  
Thomas W. Grimm ◽  
Damian van de Heisteeg
Keyword(s):  
Black Holes ◽  
Moduli Space ◽  
Mass Formula ◽  
Complex Structure ◽  
Mass Ratio ◽  
De Sitter ◽  
String Compactifications ◽  
Type Iib String Theory ◽  
Bps States ◽  
Weak Gravity

Abstract We study the charge-to-mass ratios of BPS states in four-dimensional $$ \mathcal{N} $$ N = 2 supergravities arising from Calabi-Yau threefold compactifications of Type IIB string theory. We present a formula for the asymptotic charge-to-mass ratio valid for all limits in complex structure moduli space. This is achieved by using the sl(2)-structure that emerges in any such limit as described by asymptotic Hodge theory. The asymptotic charge-to-mass formula applies for sl(2)-elementary states that couple to the graviphoton asymptotically. Using this formula, we determine the radii of the ellipsoid that forms the extremality region of electric BPS black holes, which provides us with a general asymptotic bound on the charge-to-mass ratio for these theories. Finally, we comment on how these bounds for the Weak Gravity Conjecture relate to their counterparts in the asymptotic de Sitter Conjecture and Swampland Distance Conjecture.

scholarly journals G 4 flux, algebraic cycles and complex structure moduli stabilization

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
A. P. Braun ◽  
R. Valandro
Keyword(s):  
Moduli Space ◽  
Complex Structure ◽  
Algebraic Cycles ◽  
Specific Point ◽  
Moduli Stabilization ◽  
Fermat Point

Abstract We construct G4 fluxes that stabilize all of the 426 complex structure moduli of the sextic Calabi-Yau fourfold at the Fermat point. Studying flux stabilization usually requires solving Picard-Fuchs equations, which becomes unfeasible for models with many moduli. Here, we instead start by considering a specific point in the complex structure moduli space, and look for a flux that fixes us there. We show how to construct such fluxes by using algebraic cycles and analyze flat directions. This is discussed in detail for the sextic Calabi-Yau fourfold at the Fermat point, and we observe that there appears to be tension between M2-tadpole cancellation and the requirement of stabilizing all moduli. Finally, we apply our results to show that even though symmetric fluxes allow to automatically solve several F-term equations, they typically lead to flat directions.

scholarly journals Heterotic complex structure moduli stabilization for elliptically fibered Calabi-Yau manifolds

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Wei Cui ◽  
Mohsen Karkheiran
Keyword(s):  
Spectral Data ◽  
Moduli Space ◽  
Vector Bundles ◽  
Complex Structure ◽  
Algebraic Cycles ◽  
Higgs Bundle ◽  
Moduli Stabilization ◽  
Atiyah Class ◽  
Dual Complex ◽  
Calabi Yau Manifolds

Abstract Holomorphicity of vector bundles can stabilize complex structure moduli of a Calabi-Yau threefold in N = 1 supersymmetric heterotic compactifications. In principle, the Atiyah class determines the stabilized moduli. In this paper, we study how this mechanism works in the context of elliptically fibered Calabi-Yau manifolds where the complex structure moduli space contains two kinds of moduli, those from the base and those from the fibration. Defining the bundle with spectral data, we find three types of situations when bundles’ holomorphicity depends on algebraic cycles exist only for special loci in the complex structure moduli, which allows us to stabilize both of these two moduli. We present concrete examples for each type and develop practical tools to analyze the stabilized moduli. Finally, by checking the holomorphicity of the four-flux and/or local Higgs bundle data in F-theory, we briefly study the dual complex structure moduli stabilization scenarios.

scholarly journals On de Sitter string vacua from anti-d3-branes in the large volume scenario

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Chiara Crinò ◽  
Fernando Quevedo ◽  
Roberto Valandro
Keyword(s):  
Large Volume ◽  
Complex Structure ◽  
Proof Of Concept ◽  
De Sitter ◽  
Concrete Type ◽  
Consistency Constraints ◽  
De Sitter Vacua

Abstract We consider de Sitter vacua realised in concrete type IIB Calabi-Yau compactifications with an anti D3-brane at the tip of a warped throat of Klebanov-Strassler type. The Kähler moduli are stabilised together with the complex structure modulus of the warped throat. The volume is exponentially large as in the large volume scenario (LVS). We analyse the conditions on the parameters of the EFT such that they are in the region of validity of our approximations, there are no runaway problems and the vacua satisfy all consistency constraints, such as tadpole cancellation. We illustrate our results with an explicit Calabi-Yau orientifold with two Kähler moduli and one antibrane on top of an O3-plane in a warped throat, that has the goldstino as its only massless state. The moduli are stabilised with gs∼ 0.2 and volume $$ \mathcal{V} $$ V ∼ 104 in string units, justifying the approximation used to derive the corresponding EFT. Although the model lacks chiral matter, it is presented as a proof of concept, chosen to be the simplest realisation of antibrane uplift.

scholarly journals An update on moduli stabilization with antibrane uplift

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Emilian Dudas ◽  
Severin Lüst
Keyword(s):  
Cosmological Constant ◽  
Supersymmetry Breaking ◽  
Light Field ◽  
Complex Structure ◽  
Small Scale ◽  
De Sitter ◽  
Moduli Stabilization ◽  
Matter Fields

Abstract It was recently shown that in warped compactifications based on a Klebanov-Strassler throat there is a light complex structure field, governing the size of the throat and the redshift at its tip. We show that after uplift of the cosmological constant by an anti-D3 brane at the tip of the throat, the contribution to supersymmetry breaking coming from the new light field is large. We work out the mass scales, in particular the condition for this field to be heavier than the Kähler modulus. We check that for the range of parameters relevant for the destabilization we find agreement with de Sitter swampland conjecture. Adding matter fields on distant branes, we discuss the effects on supersymmetry breaking in the observable sector. A hierarchically small scale of supersymmetry breaking translates generically into large values of localized D3 charges in the manifold.

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