On K3-fibred LARGE Volume Scenario with de Sitter vacua from anti-D3-branes

Abstract

In the context of type IIB superstring compactifications on K3-fibred (weak) Swiss-cheese Calabi Yau (CY) orientifolds, we consider the realisation of de Sitter vacua obtained through the introduction of an $$ \overline{D3} $$ D 3 ¯ -brane at the tip of a highly warped throat of Klebanov-Strassler type. Aiming to have a concrete global realisation, we perform a systematic search for the CY threefolds with 2 < h1,1< 5 arising from the Kreuzer-Skarke database, which satisfy the minimal requirements of being K3-fibred and suitable for moduli stabilisation within the LARGE Volume Scenario (LVS). In this context, after scanning the set of K3-fibred CY threefolds with a so-called diagonal del-Pezzo divisor needed for LVS, we realise that one of the main challenging requirements for having $$ \overline{D3} $$ D 3 ¯ -brane uplifting is to find a suitable orientifold involution which can simultaneously result in a sufficient large D3 tadpole charge along with the presence of suitable O3-planes. In our detailed analysis (limited to) using the CY threefolds with small h1,1, we observe that these topological requirements rule out most of the CY geometries leading to only few possibly suitable candidates for the purpose of $$ \overline{D3} $$ D 3 ¯ -brane uplifting. Subsequently, we present a global model using one such explicit K3-fibred CY threefold with h1,1 = 4 in which all the moduli can be consistently stabilised in a de Sitter minimum of the scalar potential.

Seeking de Sitter vacua in the string landscape

“…Given that the CY orientifold at hand does not have any 𝑂3-planes, the anti-𝐷3 uplifting proposal of [43,191] does not apply to our case. However, having three stacks of 𝐷7-branes intersecting at three T 2 's, there can be various other ways of inducing uplifting term which can result in dS solution.…”

“…In recent years, these corrections have received a significant amount of attention in the context of LVS moduli stabilisation and inflation, e.g. see [137,139,191].…”

“…String vacua George K. Leontaris 3. Another important class of CY threefolds consists of those which are 𝐾3-fibered and exhibit some peculiar properties leading to interesting phenomenological applications, including the well-known Fibre inflation models [44,79,92,136,137,191,236,238]. It is useful to mention a theorem of [239,240] which states that if the CY intersection polynomial is linear in the homology class D corresponding to a divisor 𝐷, then the CY threefold has the structure of a K3 or a T 4 fibration over a P 1 base, i.e.…”

“…Another issue which can be addressed only after taking the global model building aspects into account is related to satisfying the so-called tadpole cancellation conditions. In the lights of anti-D3-brane uplifting, the recent demand of constructing models with large tadpole charge [43,191] and the subsequent challenges 241] have been interesting topics to be explored.…”

Early Dark Energy in Type IIB String Theory

“…Given that in this case, in the τ s → 0 limit, the volume is determined by 2 fields, rather than the 1 of the simpler Swiss cheese geometry, one direction in the (τ 1 , τ 2 )-plane is left flat by LVS stabilization. This flat direction can be lifted by string loops [47,51,52,114], higher derivative [50] or non-perturbative corrections [115,116] to the action and can play a role either in early [47][48][49][50][51][52]117] or late time cosmology [56]. Finally, the potential of the two bulk axions θ 1 and θ 2 is generated at an even subleading order by the T 1 -and T 2 -dependent non-perturbative contributions to the superpotential.…”