Results 31 to 40 of about 110 (109)
Fortschritte der Physik, Volume 68, Issue 11-12, December 2020., 2020 Abstract We analyze to which extent the KKLT proposal for the construction of de Sitter vacua in string theory is quantitatively controlled. Our focus is on the quality of the 10d supergravity approximation. As our main finding, we uncover and quantify an issue which one may want to call the “singular‐bulk problem”.
Xin Gao +2 more
wiley +1 more source
Explicit soft supersymmetry breaking in the heterotic M-theory B − L MSSM
Journal of High Energy Physics, 2021 The strongly coupled heterotic M-theory vacuum for both the observable and hidden sectors of the B − L MSSM theory is reviewed, including a discussion of the “bundle” constraints that both the observable sector SU(4) vector bundle and the hidden sector ...
Anthony Ashmore +2 more
doaj +1 more source
Null Fluid Collapse in Rastall Theory of Gravity
Annalen der Physik, Volume 532, Issue 10, October 2020., 2020 According to general relativity, gravitational collapse of a massive star ends in a spacetime singularity. This is an extreme event that could be either hidden by a (black hole) horizon or visible to the rest of the universe (naked singularity). This phenomenon is studied within the framework of Rastall gravity and the results are compared to the ...
Amir Hadi Ziaie, Yaser Tavakoli
wiley +1 more source
Stability and vacuum energy in open string models with broken supersymmetry
Journal of High Energy Physics, 2019 We construct type I string models with supersymmetry broken by compactifi- cation that are non-tachyonic and have exponentially small effective potential at one-loop.
Steven Abel +3 more
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UV Shadows in EFTs: Accidental Symmetries, Robustness and No‐Scale Supergravity
Fortschritte der Physik, Volume 68, Issue 10, October 2020., 2020 Abstract We argue that accidental approximate scaling symmetries are robust predictions of weakly coupled string vacua, and show that their interplay with supersymmetry and other (generalised) internal symmetries underlies the ubiquitous appearance of no‐scale supergravities in low‐energy 4D EFTs.
C. P. Burgess +4 more
wiley +1 more source
Moduli stabilisation and the statistics of axion physics in the landscape
Journal of High Energy Physics, 2021 String theory realisations of the QCD axion are often said to belong to the anthropic window where the decay constant is around the GUT scale and the initial misalignment angle has to be tuned close to zero.
Igor Broeckel +4 more
doaj +1 more source
Explore and Exploit with Heterotic Line Bundle Models
Fortschritte der Physik, Volume 68, Issue 5, May 2020., 2020 Deep reinforcement learning is used to explore a class of heterotic SU(5) GUT models constructed from line bundle sums over Complete Intersection Calabi Yau (CICY) manifolds. Several experiments are performed where A3C agents are trained to search for such models. These agents significantly outperform random exploration, in the most favourable settings
M. Larfors, R. Schneider
wiley +1 more source
The Nelson‐Seiberg Theorem Generalized with Nonpolynomial Superpotentials
Advances in High Energy Physics, Volume 2020, Issue 1, 2020., 2020 The Nelson‐Seiberg theorem relates R‐symmetries to F‐term supersymmetry breaking and provides a guiding rule for new physics model building beyond the Standard Model. A revision of the theorem gives a necessary and sufficient condition to supersymmetry breaking in models with polynomial superpotentials.
Zhengyi Li +2 more
wiley +1 more source
LHC SUSY and WIMP dark matter searches confront the string theory landscape
Journal of High Energy Physics, 2019 The string theory landscape of vacua solutions provides physicists with some understanding as to the magnitude of the cosmological constant. Similar reasoning can be applied to the magnitude of the soft SUSY breaking terms in supersymmetric models of ...
Howard Baer +4 more
doaj +1 more source
Naturalness and dark matter in a realistic intersecting D6-brane model
Journal of High Energy Physics, 2018 We revisit a three-family Pati-Salam model with a realistic phenomenology from intersecting D6-branes in Type IIA string theory compactified on a T 6 /(ℤ2 × ℤ2) orientifold, and study its naturalness in view of the current LHC and dark matter searches ...
Waqas Ahmed +5 more
doaj +1 more source