{"total":13,"items":[{"citing_arxiv_id":"2605.30259","ref_index":1,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Late-time Quantum Vacuum Decay and its Cosmological Implications","primary_cat":"astro-ph.CO","submitted_at":"2026-05-28T17:22:19+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":5.0,"formal_verification":"none","one_line_summary":"Phenomenological late-time vacuum-tunneling models are fit to DESI DR2, supernova, and CMB data, allowing up to 50% vacuum-energy drop for z_t < 1 and a preferred z_t ~7 model that converts ~10% dark matter while easing cosmological tensions.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2605.27107","ref_index":11,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"A gentle introduction to the cosmological multiverse","primary_cat":"physics.pop-ph","submitted_at":"2026-05-26T14:46:08+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":0.0,"formal_verification":"none","one_line_summary":"An accessible overview of general relativity, the cosmological constant problem, and the multiverse as a hypothetical solution, while noting the unresolved measure problem of eternal inflation.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2605.05357","ref_index":10,"ref_count":1,"confidence":0.9,"is_internal_anchor":false,"paper_title":"Small Vacuum Energy and Tunneling in a Modified Bousso-Polchinski Model","primary_cat":"hep-th","submitted_at":"2026-05-06T18:34:30+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":6.0,"formal_verification":"none","one_line_summary":"In a wafer-modified Bousso-Polchinski model, 99.95% of the 532 million Calabi-Yau fourfold configurations in the Schöller-Skarke database allow vacuum energy spacings of 10^{-120} or smaller, with membrane nucleation transitions dominated by giant flux leaps under thin-wall approximations.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"In the spirit of BP, we will ignore moduli dependence and treat these quantities as independent in an effort to understand the basic physics, but in the conclusions will discuss a number of ways to make further 1More recently, it has been appreciated that there is also an exponentially large number of topologically distinct string geometries,e.g., an estimate of 10 3000 [10] and lower bound of 10 755 [11] in certain F-theory constructions. 2 progress by relaxing the assumptions. Specifically, we will carry out an analysis of the vacuum energy spacing akin to the BP result, but necessitating a saddlepoint computation for the number of flux vacua rather than a volume approximation. The result is that this model can easily account for the observed small value of the cosmological constant - in"},{"citing_arxiv_id":"2604.21970","ref_index":25,"ref_count":1,"confidence":0.9,"is_internal_anchor":false,"paper_title":"Flux Mixing and CP Violation in QCD","primary_cat":"hep-ph","submitted_at":"2026-04-23T18:00:01+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":5.0,"formal_verification":"none","one_line_summary":"Kinetic mixing between hidden-sector fluxes and QCD's topological sector shifts the effective theta angle and produces nonzero <G tilde G>.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"4The membrane configurations over which we integrate in the path integral. 5 exponential suppression of the nucleation rateΓ∼exp(−cT 4/X 3 YM)[20-22]. This system is analogous to(1 + 1)dMaxwell theory: the three-form field has no local propagating degrees of freedom while there is the Kogut-Susskind pole [23,24], theθparameter is2π-periodic due to quantization R dC∈2πZ, the \"electric field\" is also quantized [25] as in the 2d theory, i.e. ⟨⋆dC⟩=X YM k− θ 2π \u0001 , k∈Zin the limit of non-dynamical domain walls. The membrane interpolates between vacua with different values ofG˜G. Under CP or P,G˜G→ −G ˜G, which exchanges the two sides of the wall. As a result, a membrane is mapped to a membrane with opposite orientation. Differentk-sectorsareseparatedbydomainwalls/membranes, whicharehigher-dimensional"},{"citing_arxiv_id":"2604.03363","ref_index":8,"ref_count":1,"confidence":0.9,"is_internal_anchor":false,"paper_title":"Topolons: Stable Particle-Like Remnants of Collapsed Vacuum Bubbles","primary_cat":"gr-qc","submitted_at":"2026-04-03T17:52:53+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":6.0,"formal_verification":"none","one_line_summary":"Vacuum bubbles carrying quantized monopole flux on their walls collapse to stable particle-like remnants whose mass is fixed by the wall scale and conserved flux.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"medium characterized by a conserved variableq, which can be realized through a three-form gauge field and whose equilibrium value relaxes the vacuum pres- sure toward zero [9, 10, 11]. In string compactifications, multiple four-form fluxes generate a dense discretuum of effective cosmological constants, making small positive Λ possible as one choice in a large landscape [8]. Four-form sec- tors also play a central role in vacuum energy sequestering, where global or local constraints enforced by four-forms remove matter vacuum energy from the grav- itational field equations [12, 13, 14, 15, 16, 17, 18, 19]. More broadly, renewed interest in vacuum energy and late-time acceleration has also been sharpened by current large-scale-structure data, including recent DESI results for dynamical"},{"citing_arxiv_id":"2603.25797","ref_index":41,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Dark energy from string theory: an introductory review","primary_cat":"hep-th","submitted_at":"2026-03-26T18:05:41+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":2.0,"formal_verification":"none","one_line_summary":"String theory imposes constraints on dark energy but permits various construction attempts for de Sitter vacua and single-field exponential quintessence models despite obstructions.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"On the mathematical side, the review of group manifolds and relevant Lie algebras (e.g. solvable) provided in Section 4.1.1 and Appendix C may be of broader interest. 1.2.2 Topics not covered Several important topics, related to above questions, are not covered in this article; we briefly discuss them here. Let us start with thecosmological constant problem[40], re- viewed e.g. in [41, 42]. Assuming that dark energy is given by a cosmological constant, we obtain Λ =V 0/M2 p = 3H 2 0 ΩDE (see Appendix B). Using the data from [43], namely H0 = 67.4km.s −1.M pc−1 = 5.87·10 −61 Mp and ΩDE = 0.685, one gets Λ = 7.08·10 −121 M 2 p orV 0 = 24.9meV 4. One part of the problem is the huge hierarchy between this observed Λ and the \"natural\" fundamental scaleM p, which is not easy to engineer in concrete models."},{"citing_arxiv_id":"2602.19812","ref_index":97,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"dS$^4$ Metamorphosis","primary_cat":"hep-th","submitted_at":"2026-02-23T13:12:14+00:00","verdict":"CONDITIONAL","verdict_confidence":"MODERATE","novelty_score":7.0,"formal_verification":"none","one_line_summary":"Higher spin gravity path integral on S^4 glues to an Sp(N) or superconformal S^3 boundary theory, giving leading contribution 2^N with one-loop cancellations.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2601.15592","ref_index":19,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Extended symmetry of the Maxwell theory with a gauge coupling constant as a conserved charge","primary_cat":"hep-th","submitted_at":"2026-01-22T02:33:28+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":5.0,"formal_verification":"none","one_line_summary":"Maxwell theory with auxiliary fields for the coupling constant breaks symmetries that BFT restores, making the original theory a gauge-fixed version of the extended symmetric theory.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2509.08390","ref_index":34,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Gravitational constant as a conserved charge in black hole thermodynamics","primary_cat":"hep-th","submitted_at":"2025-09-10T08:33:14+00:00","verdict":"CONDITIONAL","verdict_confidence":"LOW","novelty_score":6.0,"formal_verification":"none","one_line_summary":"Using two scalar-gauge pairs and the off-shell ADT formalism in a modified Einstein-Hilbert theory, the authors derive conserved charges for mass, cosmological constant, and G that yield a consistent extended thermodynamic first law and Smarr formula.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2507.02787","ref_index":3,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Stability of non-supersymmetric vacua from calibrations","primary_cat":"hep-th","submitted_at":"2025-07-03T16:50:45+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":5.0,"formal_verification":"none","one_line_summary":"Uses calibrations to protect examined non-supersymmetric AdS vacua in type II string theory from D-brane mediated decays, including abelian bound states.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"2402.07716","ref_index":151,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"$\\Lambda_{\\rm s}$CDM cosmology from a type-II minimally modified gravity","primary_cat":"astro-ph.CO","submitted_at":"2024-02-12T15:29:10+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":7.0,"formal_verification":"none","one_line_summary":"Λ_s VCDM is a predictive model combining Λ_s CDM with VCDM gravity via an auxiliary scalar field and sigmoid-smoothed potentials to enable stable mirror AdS-to-dS transitions with possible transient acceleration.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"[ 145], by using the St¨ uckelberg trick, it is possible to rewrite the theory in a fully covariant form. A time- like St¨ uckelberg field, i.e., a chronon field, is present and acquires a time-like VEV on any background of the theory. On each of these backgrounds, we quantize all the fields following the quantum field theory (QFT) procedures commonly employed on curved spacetimes [ 151]. This approach also applies to other minimal theories, such as the Cuscuton [152]. mogeneous and isotropic background, it can modify the Hubble expansion rate while maintaining only two gravita- tional degrees of freedom, as in GR. In general, this allows for a spectrum of possibilities typically much broader than in scalar-tensor theories. For the latter, generally, the"},{"citing_arxiv_id":"2008.10625","ref_index":190,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"Lectures on Naturalness, String Landscape and Multiverse","primary_cat":"hep-th","submitted_at":"2020-08-24T18:01:55+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":1.0,"formal_verification":"none","one_line_summary":"Lecture notes providing a technical introduction to naturalness problems and the string theory landscape for graduate students.","context_count":0,"top_context_role":null,"top_context_polarity":null,"context_text":null},{"citing_arxiv_id":"0905.4720","ref_index":29,"ref_count":1,"confidence":0.98,"is_internal_anchor":true,"paper_title":"String Axiverse","primary_cat":"hep-th","submitted_at":"2009-05-28T19:38:46+00:00","verdict":"UNVERDICTED","verdict_confidence":"LOW","novelty_score":7.0,"formal_verification":"none","one_line_summary":"String theory predicts an axiverse of ultralight axions whose effects on CMB polarization, matter power spectrum, and black hole superradiance can be probed by future astrophysical experiments.","context_count":1,"top_context_role":"background","top_context_polarity":"background","context_text":"In Section 2 we show that there are a variety of observational windows on such axions. 1.3 Wilsonian Scanning of the Cosmological Constant Interestingly, the same number-of order several hundred cycles-is also suggested by the require- ment that there are enough different fluxes to implement the Bousso-Polchinski mechanism for scanning the cosmological constant [29, 30]. The famous 10 500 estimate for the number of different string vacua comes out exactly as a result of having 500 different fluxes, corresponding to different cycles. At this point one may wonder whether the axion potential itself may be responsible for the scanning of the cosmological constant in the presence of several hundred axions. Indeed, as explained in Ref."}],"limit":50,"offset":0}