scholarly journals Sharpening the boundaries between flux landscape and swampland by tadpole charge

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Keiya Ishiguro ◽  
Hajime Otsuka
Keyword(s):  
Flux Compactifications ◽  
Scalar Potential ◽  
Low Energy ◽  
The Other ◽  
Effective Theory ◽  
Taylor Model ◽  
De Sitter ◽  
Cancellation Condition ◽  
Vacuum Structure ◽  
De Sitter Vacua

Abstract We investigate the vacuum structure of four-dimensional effective theory arising from Type IIB flux compactifications on a mirror of the rigid Calabi-Yau threefold, corresponding to a T-dual of the DeWolfe-Giryavets-Kachru-Taylor model in Type IIA flux compactifications. By analyzing the vacuum structure of this interesting corner of string landscape, it turns out that there exist perturbatively unstable de Sitter (dS) vacua in addition to supersymmetric and non-supersymmetric anti-de Sitter vacua. On the other hand, the stable dS vacua appearing in the low-energy effective action violate the tadpole cancellation condition, indicating a strong correlation between the existence of dS vacua and the flux-induced D3-brane charge (tadpole charge). We also find analytically that the tadpole charge constrained by the tadpole cancellation condition emerges in the scalar potential in a nontrivial way. Thus, the tadpole charge would restrict the existence of stable dS vacua, and this fact underlies the statement of the dS conjecture. Furthermore, our analytical and numerical results exhibit that distributions of $$ \mathcal{O}(1) $$ O 1 parameters in expressions of several swampland conjectures peak at specific values.

scholarly journals Emergent $$\alpha $$-like fermionic vacuum structure and entanglement in the hyperbolic de Sitter spacetime

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
Sourav Bhattacharya ◽  
Shankhadeep Chakrabortty ◽  
Shivang Goyal
Keyword(s):  
Quantum Correlations ◽  
Dirac Field ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Local Modes ◽  
Vacuum Structure ◽  
Continuous Parameter ◽  
Sitter Spacetime ◽  
Global Modes ◽  
De Sitter Vacua

Abstract We report a non-trivial feature of the vacuum structure of free massive or massless Dirac fields in the hyperbolic de Sitter spacetime. Here we have two causally disconnected regions, say R and L separated by another region, C. We are interested in the field theory in $$R\cup L$$R∪L to understand the long range quantum correlations between R and L. There are local modes of the Dirac field having supports individually either in R or L, as well as global modes found via analytically continuing the R modes to L and vice versa. However, we show that unlike the case of a scalar field, the analytic continuation does not preserve the orthogonality of the resulting global modes. Accordingly, we need to orthonormalise them following the Gram–Schmidt prescription, prior to the field quantisation in order to preserve the canonical anti-commutation relations. We observe that this prescription naturally incorporates a spacetime independent continuous parameter, $$\theta _{\mathrm{RL}}$$θRL, into the picture. Thus interestingly, we obtain a naturally emerging one-parameter family of $$\alpha $$α-like de Sitter vacua. The values of $$\theta _{\mathrm{RL}}$$θRL yielding the usual thermal spectra of massless created particles are pointed out. Next, using these vacua, we investigate both entanglement and Rényi entropies of either of the regions and demonstrate their dependence on $$\theta _{\mathrm{RL}}$$θRL.

scholarly journals de Sitter vacua from nonperturbative flux compactifications

2014 ◽  
Vol 90 (2) ◽  
Author(s):  
Johan Blåbäck ◽  
Diederik Roest ◽  
Ivonne Zavala
Keyword(s):  
Flux Compactifications ◽  
De Sitter ◽  
De Sitter Vacua

scholarly journals Higgs inflation and its extensions and the further refining dS swampland conjecture

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Yang Liu
Keyword(s):  
Scalar Potential ◽  
Cosmological Parameters ◽  
The Other ◽  
De Sitter ◽  
Inflation Model ◽  
Link Type ◽  
Second Derivatives ◽  
The One ◽  
Derivatives Of ◽  
Inflationary Models

AbstractOn the one hand, Andriot and Roupec (Fortsch Phys, 1800105, 2019) proposed an alternative refined de Sitter conjecture, which gives a natural condition on a combination of the first and second derivatives of the scalar potential (Andriot and Roupec 2019). On the other hand, in our previous article (Liu in Eur Phys J Plus 136:901, 2021) , we have found that Palatini Higgs inflation model is in strong tension with the refined de Sitter swampland conjecture (Liu 2021). Therefore, following our previous research, in this article we examine if Higgs inflation model and its two variations: Palatini Higgs inflation and Higgs-Dilaton model (Rubio in Front Astron Space Sci, 10.3389/fspas.2018.00050, 2019) can satisfy the “further refining de Sitter swampland conjecture” or not. Based on observational data (Ade et al., Phys Rev Lett 121:221301, 2018; Akrami et al., Planck 2018 results. X. Constraints on inflation, arXiv:1807.06211 [astro-ph.CO], 2018; Aghanim et al., Planck 2018 results: VI. Cosmological parameters, arXiv:1807.06209 [astro-ph.CO], 2018), we find that these three inflationary models can always satisfy this new swampland conjecture if only we adjust the relevant parameters a, $$b = 1-a$$ b = 1 - a and q. Therefore, if the “further refining de Sitter swampland conjecture” does indeed hold, then the three inflationary models might all be in “landscape”.

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 A stringy perspective on the coincidence problem

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Francesc Cunillera ◽  
Antonio Padilla
Keyword(s):  
Phase Transition ◽  
Dark Energy ◽  
Early Universe ◽  
Low Energy ◽  
De Sitter ◽  
Coincidence Problem ◽  
String Compactifications ◽  
Slow Roll ◽  
De Sitter Vacua ◽  
Quintessence Field

Abstract We argue that, for string compactifications broadly consistent with swampland constraints, dark energy is likely to signal the beginning of the end of our universe as we know it, perhaps even through decompactification, with possible implications for the cosmological coincidence problem. Thanks to the scarcity (absence?) of stable de Sitter vacua, dark energy in string theory is assumed to take the form of a quintessence field in slow roll. As it rolls, a tower of heavy states will generically descend, triggering an apocalyptic phase transition in the low energy cosmological dynamics after at most a few hundred Hubble times. As a result, dark energy domination cannot continue indefinitely and there is at least a percentage chance that we find ourselves in the first Hubble epoch. We use a toy model of quintessence coupled to a tower of heavy states to explicitly demonstrate the breakdown in the cosmological dynamics as the tower becomes light. This occurs through a large number of corresponding particles being produced after a certain time, overwhelming quintessence. We also discuss some implications for early universe inflation.

scholarly journals de Sitter vacua from ten dimensions

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Shamit Kachru ◽  
Manki Kim ◽  
Liam McAllister ◽  
Max Zimet
Keyword(s):  
Equations Of Motion ◽  
Effective Theory ◽  
De Sitter ◽  
Stress Energy ◽  
Exact Agreement ◽  
De Sitter Vacua ◽  
Brane Action

Abstract We analyze the de Sitter construction of [1] using ten-dimensional supergravity, finding exact agreement with the four-dimensional effective theory. Starting from the fermionic couplings in the D7-brane action, we derive the ten-dimensional stress-energy due to gaugino condensation on D7-branes. We demonstrate that upon including this stress-energy, as well as that due to anti-D3-branes, the ten-dimensional equations of motion require the four-dimensional curvature to take precisely the value determined by the four-dimensional effective theory of [1].

scholarly journals Resolving spacetime singularities in flux compactifications & KKLT

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Federico Carta ◽  
Jakob Moritz
Keyword(s):  
Field Theory ◽  
Flux Compactifications ◽  
Effective Field Theory ◽  
Bound States ◽  
Effective Field ◽  
Low Energy ◽  
De Sitter ◽  
Yang Mills ◽  
Type Iib String Theory ◽  
De Sitter Vacuum

Abstract In flux compactifications of type IIB string theory with D3 and seven-branes, the negative induced D3 charge localized on seven-branes leads to an apparently pathological profile of the metric sufficiently close to the source. With the volume modulus stabilized in a KKLT de Sitter vacuum this pathological region takes over a significant part of the entire compactification, threatening to spoil the KKLT effective field theory. In this paper we employ the Seiberg-Witten solution of pure SU(N) super Yang-Mills theory to argue that wrapped seven-branes can be thought of as bound states of more microscopic exotic branes. We argue that the low-energy worldvolume dynamics of a stack of n such exotic branes is given by the (A1, An−1) Argyres-Douglas theory. Moreover, the splitting of the perturbative (in α′) seven-brane into its constituent branes at the non-perturbative level resolves the apparently pathological region close to the seven-brane and replaces it with a region of $$ \mathcal{O} $$ O (1) Einstein frame volume. While this region generically takes up an $$ \mathcal{O} $$ O (1) fraction of the compactification in a KKLT de Sitter vacuum we argue that a small flux superpotential dynamically ensures that the 4d effective field theory of KKLT remains valid nevertheless.

scholarly journals A note on low energy effective theory of chromo-natural inflation in the light of BICEP2 results

2015 ◽  
Vol 30 (11) ◽  
pp. 1550040 ◽  
Author(s):  
Anindita Bhattacharjee ◽  
Atri Deshamukhya ◽  
Sudhakar Panda
Keyword(s):  
Experimental Data ◽  
Recent Result ◽  
Observational Data ◽  
Parameter Space ◽  
Low Energy ◽  
The Other ◽  
Effective Theory ◽  
Inflation Model ◽  
Upper Limit ◽  
Inflationary Models

Recent result of BICEP2, revealing a larger value of tensor to scalar ratio (r), has opened up new investigations of the inflationary models to fit the experimental data. The experiment needs to reconfirm the results, specifically the consistency between Planck and BICEP2. On the other hand, the combined analysis of Planck and BICEP2, including the dust polarization uncertainty, brings down the upper limit on r. In this paper, we re-examine the low energy effective theory of chromo-natural inflation model and its generalization in view of such observational data. We find that the parameter space of the model admits a large value of r as well as other cosmological observables consistent with data.

BLACK HOLE FORMATION VIA TACHYON CONDENSATION

2008 ◽  
Vol 23 (14n15) ◽  
pp. 2176-2177
Author(s):  
TAKAO SUYAMA
Keyword(s):  
Black Hole ◽  
Tachyon Condensation ◽  
Closed String ◽  
Space Time ◽  
Low Energy ◽  
The Other ◽  
Effective Theory ◽  
Classical Solutions ◽  
Hole Formation ◽  
Black Hole Formation

We investigate a possibility for a black hole to be created during closed string tachyon condensation. For the case of a bulk closed string tachyon, we find classical solutions of a low energy effective theory which has a black hole in the space-time. On the other hand, for the case of a localized closed string tachyon, a black hole, if created, would be of the string size and it would quickly evaporate.

scholarly journals de Sitter vacua and supersymmetry breaking in six-dimensional flux compactifications

2016 ◽  
Vol 94 (2) ◽  
Author(s):  
Wilfried Buchmuller ◽  
Markus Dierigl ◽  
Fabian Ruehle ◽  
Julian Schweizer
Keyword(s):  
Flux Compactifications ◽  
Supersymmetry Breaking ◽  
De Sitter ◽  
De Sitter Vacua
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