Based on the flux‐scaling scenario we study a model consisting on Type IIB string theory compactified on a Calabi‐Yau manifold with a frozen complex structure in the presence of generic fluxes. The ...model contains (meta)stable Minkowski and de Sitter vacua as well as inflationary directions driven by two independent linear combination of axions. Due to a numerical control by fluxes, we show that cosmological parameters as the spectral index, tensor‐to‐scalar ratio and non‐Gaussianities can be kept within observed bounds while preserving the desired hierarchies on physical scales. Moreover we compute the deviation of the inflationary trajectories from geodesics on field space in terms of the fluxes showing that for some regions, they fulfill the recent proposed swampland criterion for multi‐field scenarios.
Based on the flux‐scaling scenario a model is studied consisting on Type IIB string theory compactified on a Calabi‐Yau manifold with a frozen complex structure in the presence of generic fluxes. The model contains (meta)stable Minkowski and de Sitter vacua as well as inflationary directions driven by two independent linear combination of axions. Due to a numerical control by fluxes, the authors show that cosmological parameters as the spectral index, tensor‐to‐scalar ratio and non‐Gaussianities can be kept within observed bounds while preserving the desired hierarchies on physical scales. Moreover The deviation of the inflationary trajectories from geodesics on field space is computed in terms of the fluxes. It is shown that for some regions, they fulfill the recent proposed swampland criterion for multi‐field scenarios.
By implementing an error function on a Machine Learning algorithm we look for minimal conditions to construct stable Anti de Sitter and de Sitter vacua from dimensional type IIB String theory ...compactification on Kähler manifolds with torsion. This allows to have contributions to the scalar potential from the five-form flux and from D-branes wrapping torsional cycles, interpreted as non-BPS states. The former implies the possibility to construct stable AdS vacua while the latter constitutes a mechanism to uplift AdS to dS vacua. Particularly we consider
D
5
^
non-BPS states to uplift the stable AdS vacua to an (apparently) stable dS minimum. Both results – the generation of an AdS vacuum and the corresponding uplifting to a dS one – are restricted to a certain type of configurations, specifically with the number of
O
3 orientifolds bounded from below by the number of
D
3-branes and fluxes. Under these conditions, we report over 170 dS (classical) stable vacua. In all of them, the uplifted effective potential becomes very flat indicating the presence of possible sources of instabilities. We comment on their relationship with the Swampland Conjectures.
We compute the Galois group of a polynomial whose roots are determined by the critical points of a scalar potential in type IIB compactifications. We focus our study on certain perturbative models ...where it is feasible to construct a de Sitter vacuum within the effective theory by introducing non-geometric fluxes, D-branes or non-BPS states. Our findings clearly show that all de Sitter vacua derived from lifting AdS stable vacua are associated with an unsolvable Galois group. This suggests a deeper connection between the fundamental principles of Galois theory and its applications in the construction of dS vacua.
•In the present manuscript it is demonstrated that all de Sitter vacua from uplifting Anti-de Sitter stable vacua have associated a unsolvable Galois groups.•Due to their association with unsolvable Galois groups, all dS vacua lack analytic solutions.•The findings significantly impact the string theory landscape, offering a new perspective on the complexity of scalar potentials and its critical points as well as the stability of dS spaces.•Utilizing Galois theory to explore scalar potentials introduces a novel methodology, bridging advanced mathematical theories with string phenomenology and opening new research avenues for dS spaces in string theory.
Testing swampland conjectures with machine learning Bizet, Nana Cabo; Damian, Cesar; Loaiza-Brito, Oscar ...
The European physical journal. C, Particles and fields,
08/2020, Letnik:
80, Številka:
8
Journal Article
Recenzirano
Odprti dostop
We consider Type IIB compactifications on an isotropic torus
T
6
threaded by geometric and non geometric fluxes. For this particular setup we apply supervised machine learning techniques, namely an ...artificial neural network coupled to a genetic algorithm, in order to obtain more than sixty thousand flux configurations yielding to a scalar potential with at least one critical point. We observe that both stable AdS vacua with large moduli masses and small vacuum energy as well as unstable dS vacua with small tachyonic mass and large energy are absent, in accordance to the refined de Sitter conjecture. Moreover, by considering a hierarchy among fluxes, we observe that perturbative solutions with small values for the vacuum energy and moduli masses are favored, as well as scenarios in which the lightest modulus mass is much smaller than the corresponding AdS vacuum scale. Finally we apply some results on random matrix theory to conclude that the most probable mass spectrum derived from this string setup is that satisfying the Refined de Sitter and AdS scale conjectures.
A
bstract
We study a Type IIB isotropic toroidal compactification with non-geometric fluxes. Under the assumption of a hierarchy on the moduli, an effective scalar potential is constructed showing a ...runaway direction on the real part of the Kähler modulus while the rest of the moduli are stabilized. For the effective model to be consistent it is required that displacements in the field space are finite. Infinite distances in field space would imply a breakdown in the hierarchy assumption on the moduli. In this context, the Swamp-land Distance Conjecture is satisfied suggesting the possibility of leaving or entering the Swampland by a parametric control of the fluxes. This is achieved upon allowing the non-geometric fluxes to take fractional values. In the process we are able to compute the cut-off scale below which the theory is valid, completely depending on the flux configuration. We also report on the appearance of a discrete spectrum of values for the string coupling at the level of the effective theory.
In this note, we present a scenario in which the existence of dS vacua is jeopardized by topological transitions between non-BPS branes and fluxes in type IIB toroidal compactifications. We focus our ...study on a six-dimensional torus compactification modded out by an orientifold three-plane. In particular, we consider the presence of non-BPS five branes, which allows the construction of apparent stable dS vacua. Since moduli stabilization requires the presence of NS–NS fluxes, we also describe the minimal required conditions to avoid the appearance of Freed–Witten anomalies. Cancellation of these anomalies implies a topological transformation between non-BPS states and fluxes with the same discrete K-theory charge. After the transition, we observe that the scalar potential undergoes major changes, implying that the dS vacua are unstable. We discuss a scenario in which, even if the discrete K-theory charge is globally canceled, the above transitions could still be relevant, allowing the existence of short-lived dS minima. We briefly comment on how these implications seem to be in concordance with the Refined de Sitter and Trans-Planckian Censorship Conjectures.
•Specific scenarios where non-BPS D5̂-branes are necessary to have dS vacua.•Topological transformation between D5̂-branes and f1 discrete forms.•dS vacua is jeopardized by topological transitions between branes and fluxes.•A non-trivial tadpole cancellation for discrete K-theory charge.•Scenarios with zero discrete charge contributes non-trivialy to the scalar potential.
Meromorphic flux compactification Damian, Cesar; Loaiza-Brito, Oscar
The journal of high energy physics,
04/2017, Letnik:
2017, Številka:
4
Journal Article
Recenzirano
Odprti dostop
A
bstract
We present exact solutions of four-dimensional Einstein’s equations related to Minkoswki vacuum constructed from Type IIB string theory with non-trivial fluxes. Following
1
,
2
we study a ...non-trivial flux compactification on a fibered product by a four-dimensional torus and a two-dimensional sphere punctured by 5- and 7-branes. By considering only 3-form fluxes and the dilaton, as functions on the internal sphere coordinates, we show that these solutions correspond to a family of supersymmetric solutions constructed by the use of G-theory. Meromorphicity on functions constructed in terms of fluxes and warping factors guarantees that flux and 5-brane contributions to the scalar curvature vanish while fulfilling stringent constraints as tadpole cancelation and Bianchi identities. Different Einstein’s solutions are shown to be related by U-dualities. We present three supersymmetric non-trivial Minkowski vacuum solutions and compute the corresponding soft terms. We also construct a non-supersymmetric solution and study its stability.
We present a proposal to relate the de Sitter conjecture (dSC) with the time dependence of fluxes via the covariant entropy bound (CEB). By assuming an early phase of accelerated expansion where the ...CEB is satisfied, we take into account a contribution from time-dependent flux compactification to the four-dimensional entropy which establishes a bound on the usual slow-roll parameters ηH and ϵH. We also show an explicit calculation of entropy from a toroidal flux compactification, from a transition amplitude of time-dependent fluxes which allows us to determine the conditions on which the bounds on the slow-roll parameters are in agreement to the dSC.
Mirror quintic vacua: hierarchies and inflation Bizet, Nana Cabo; Loaiza-Brito, Oscar; Zavala, Ivonne
The journal of high energy physics,
10/2016, Letnik:
2016, Številka:
10
Journal Article
Recenzirano
Odprti dostop
A
bstract
We study the moduli space of type IIB string theory flux compactifications on the mirror of the CY quintic 3-fold in
ℙ
4
. We focus on the dynamics of the four dimensional moduli space, ...defined by the axio-dilaton τ and the complex structure modulus
z
. The
z
-plane has critical points, the conifold, the orbifold and the large complex structure with non trivial monodromies. We find the solutions to the Picard-Fuchs equations obeyed by the periods of the CY in the full
z
-plane as a series expansion in
z
around the critical points to arbitrary order. This allows us to discard fake vacua, which appear as a result of keeping only the leading order term in the series expansions. Due to monodromies vacua are located at a given sheet in the
z
-plane. A dS vacuum appears for a set of fluxes. We revisit vacua with hierarchies among the 4D and 6D physical scales close to the conifold point and compare them with those found at leading order in 1, 2. We explore slow-roll inflationary directions of the scalar potential by looking at regions where the multi-field slow-roll parameters
ϵ
and
η
are smaller than one. The value of ϵ depends strongly on the approximation of the periods and to achieve a stable value, several orders in the expansion are needed. We do not find realizations of single field axion monodromy inflation. Instead, we find that inflationary regions appear along linear combinations of the four real field directions and for certain configurations of fluxes.
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