Pith. sign in

REVIEW 4 major objections 4 minor 104 references

A one-variable Hamiltonian for the bubble radius in late-time de Sitter reproduces the Coleman–De Luccia decay rate for every transition type, with the bubble going on shell at the parent horizon.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-04 01:08 UTC pith:GT7JSGG2

load-bearing objection A serious, internally consistent Hamiltonian derivation that recovers CDL rates, but the Type-B/up match hinges on treating a branch point at R=1/H as a WKB endpoint—plausible, not yet demonstrated. the 4 major comments →

arxiv 2608.00159 v1 pith:GT7JSGG2 submitted 2026-07-31 hep-th gr-qc

The Lorentzian Geometry of Tunneling in Global de Sitter at Late Time

classification hep-th gr-qc
keywords Coleman–De Lucciade Sitter vacuum decayType–B instantonsup-tunnelingWheeler–DeWittWKB approximationdomain wallsbubbles of nothing
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper tries to establish that the standard Coleman–De Luccia (CDL) exponential decay rates for vacuum transitions in de Sitter space remain correct even in the gravity-dominated regimes—Type–B transitions and up-tunneling—where the usual Euclidean-instanton picture cannot be given a late-time Lorentzian interpretation. The authors build a quantum-mechanical model whose only degree of freedom is the radius of a thin domain wall in a late-time, effectively flat-sliced de Sitter background, and compute the WKB tunneling exponent for a bubble that starts at zero size, grows off shell, and goes on shell only after reaching the parent de Sitter horizon. They find exactly the CDL exponent in every regime, and explain the agreement as two different analytic continuations of one unique on-shell trajectory. A reader should care because this supplies a concrete late-time Lorentzian meaning for vacuum decay in the otherwise pathological Type–B and up-tunneling cases, and it changes how one approaches the instability of the domain walls that populate the string-theoretic flux landscape.

Core claim

Central claim: a one-variable Hamiltonian—the domain-wall radius R in the flat-slicing, late-time limit of de Sitter—reproduces the full Coleman–De Luccia (CDL) WKB exponent for every dS→dS transition type (A-down, B-down, A-up, B-up) and for bubbles of nothing. In gravity-dominated cases the bubble is born at zero radius in a large parent de Sitter, grows off shell, and goes on shell at the parent horizon R=1/H_1, where Im p_R abruptly vanishes. The computed exponent B=∫2 Im p_R dR matches B_CDL in all cases because the tunneling and CDL trajectories are two analytic continuations of one on-shell solution; their integrals differ by a constant that cancels the CDL background subtraction.

What carries the argument

The load-bearing object is the Hamiltonian constraint H=0 for a single degree of freedom R, the domain-wall radius, derived from the Einstein–Hilbert action in dS flat slicing (Eqs. (4.24)/(4.47)). With the noncanonical momentum p_R, the WKB tunneling exponent is B=∫_0^{R_on-shell} 2 Im p_R dR. The calculation hinges on the branch structure of the complex functions entering H and p_R: arctanh(s) and the square roots √(1−s²), √B change sheets at R=R_crit and R=1/H_1, and the physically selected 'tunneling sheet' gives Im p_R>0 with minimal positive value. For Type–B/up-tunneling, the on-shell point is R=1/H_1, and the sheet shift iπ in arctanh(s) is exactly compensated by the CDL background s

Load-bearing premise

The calculation treats the bubble radius as the only dynamical variable and trusts a leading-order WKB exponent even though WKB breaks down exactly where the bubble goes on shell (R=1/H_1) and the gauge is completely fixed before quantization; if that treatment is not valid, the recovered CDL exponents would be an artifact of the approximation rather than a property of the quantum state.

What would settle it

A direct Lorentzian gravitational path-integral evaluation of the Type–B up-tunneling exponent—or an exact numerical solution of the full Wheeler–DeWitt equation in the one-variable model—that yields a suppression different from B_CDL would refute the central claim.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • The CDL rate for Type–B down-tunneling and up-tunneling is confirmed from a purely Lorentzian, late-time calculation, so those transitions no longer require an interpretation in which the whole parent dS disappears at its waist.
  • Late-time vacuum decay is local: bubbles nucleate at small radius inside a large parent dS and go on shell at the parent horizon, so the multiverse is not in the causal future of a single tunneling event.
  • The instability of flux-landscape domain walls is reframed: a Type–B transition can be described by the late-time Hamiltonian picture, and the wall goes on shell at the horizon rather than at the waist, avoiding the global crunch that naively follows from combining unstable walls with the waist interpretation of CDL.
  • The same WKB machinery yields explicit tunneling exponents for bubbles of nothing, giving a simpler testing ground for the dS–dS results.
  • Agreement between the Euclidean and Lorentzian methods is traced to a sheet-transition identity relating the two momenta, so the two frameworks are not independent computations but two branches of one complex trajectory.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If leading-order WKB is reliable, the same Hamiltonian method should yield the next-order prefactor for Type–B transitions, which would sharpen predictions for the string landscape.
  • The horizon-shell limit hints at a brane–anti-brane pair-creation picture near the parent horizon; this could be tested by examining the subleading structure of the wavefunction or the finite-action paths that go on shell beyond R=1/H_1.
  • The method should extend to domain walls with moduli-dependent tension, as in the unstable-wall problem, potentially settling whether a small residual flux-transition rate survives.
  • Comparing this one-dimensional WKB exponent with a direct Lorentzian gravitational path integral in the Type–B regime would locate the limits of the approximation and test the exactness of the CDL exponent.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

4 major / 4 minor

Summary. The paper studies late-time vacuum decay in de Sitter space using a Hamiltonian minisuperspace model in which the only dynamical variable is the domain-wall radius R. The authors start from the Einstein–Hilbert action with a thin domain wall, take the late-time/small-angle limit (flat slicing), derive a one-variable Hamiltonian and the associated Wheeler–DeWitt equation, and then compute decay exponents by the WKB formula B = ∫ 2 Im p_R dR. The computation is carried out both for bubbles of nothing and for dS-to-dS transitions, covering Type–A and Type–B, down- and up-tunneling. The central claim is that, despite the very different off-shell geometries, the WKB exponent reproduces the Coleman–De Luccia rate in all cases, including the previously problematic Type–B and Type–A up-tunneling regimes, where the wall goes on shell at the parent horizon R = 1/H1. The paper also discusses the Larfors–Johnson problem and argues that the Lorentzian late-time picture avoids the multiverse apocalypse that would follow from combining unstable domain walls with the naive CDL interpretation.

Significance. If the central claim is correct, the paper resolves a long-standing interpretational puzzle: it provides a Lorentzian late-time description of Type–B and up-tunneling transitions whose rate agrees with CDL, thereby supporting the standard multiverse rates. The calculation is largely self-contained and is presented with unusual transparency: the explicit integrals in §4.2.2 and §4.3.2, the branch tables in Appendix A, and the honest discussion of the WKB limitations are all valuable. There is no fitted parameter; the CDL rate emerges from the integral and branch choice. The potential implication for the string landscape and the Larfors–Johnson problem is significant. However, the load-bearing WKB step at the on-shell horizon is not justified, and the authors themselves flag that the WKB approximation breaks down in exactly the region that controls the Type–B/up-tunneling agreement. Thus the result is important and likely correct, but the current manuscript does not fully establish it.

major comments (4)
  1. [§4.2.2, Eq. (4.29), (4.40), (4.41), Fig. 9] The endpoint R = 1/H is not a turning point where p_R = 0; it is a branch point of p_R(s(R)) at s = -1, where Re(arctanh s) diverges and Im p_R is discontinuous (the π shift in Eq. (4.37)). Standard WKB connection formulas, including those for noncanonical Hamiltonians, are derived for smooth turning points. Applying Eq. (4.29) across this branch point has no supplied justification. The authors concede in §4.2.2 that the analysis is 'questionable in the region 1 - RH ≪ 1', but the defense that 'most of the integral is not dependent on this region' is not valid: the Region-2 contribution Eq. (4.40) is the entire interval Rcrit < R < 1/H, and it is precisely the term that cancels the Rcrit^2 δ/2 part of Eq. (4.38) to produce the CDL value. This is not a negligible endpoint correction. A proper connection formula or explicit complex-contour argument around the s = -1 branch point is needed
  2. [§4.3.2, Eq. (4.60) and Appendix A, Tables 1–2] The same issue repeats for dS-to-dS transitions. For Type–B down- and up-tunneling, the region Rcrit < R < 1/H1 contributes B = ∫ πR dR, which is what turns the Region-1 result into B_CDL. The branch assignment δ_s = π, δ_A = 0 in Table 2 is an input, selected by the requirement Im(p_R) ≥ 0 with minimal positive value. The authors do not derive this selection from a boundary condition on the WDW wavefunction or from a singularity-free connection formula. Since the Hamiltonian is noncanonical and all gauge freedom is fixed before quantization (§4.1, §6), there is no independent consistency check. The branch choice could change the exponent by O(1), and hence the agreement with CDL may be an artifact of the analytic continuation rather than a property of the Lorentzian tunneling process.
  3. [§5.2.3, 'Quick argument for the relation to CDL'] This subsection is supposed to provide a simpler relation to CDL, but the authors themselves state that the argument is 'not completely convincing' and that the explicit computations of the previous subsection are needed. Since the explicit computations are exactly the ones whose endpoint treatment is in question, this creates a circularity: the quick argument relies on the CDL trajectory, while the explicit computation relies on the unjustified WKB branch-point handling. The sentence 'It is possible but unilluminating to explicitly show this' is not an adequate substitute for the missing derivation. The manuscript needs either a rigorous connection formula or an independent path-integral check for the Type–B/up cases.
  4. [§4.2.2 and §6, 'reliability of WKB'] The paper openly lists as an open question: 'in the region where our bubble goes on shell, the WKB approximation clearly breaks down. Can one quantify the error introduced?' This is an honest but important admission. The claim that the rate is still reliable because the potential barrier is large in most of the integration domain is plausible but not demonstrated. In particular, the divergence of Re p_R near R = 1/H and the discontinuity of Im p_R mean that the usual WKB error estimate does not apply. I would ask the authors to quantify the subleading corrections or to provide a numerical/independent check of the Type–B/up exponent.
minor comments (4)
  1. [Introduction] There are several formatting typos, e.g. 'Wenotethat' should be 'We note that', and 'Type–B' / 'Type B' are used inconsistently (e.g. Section 2.3). These are cosmetic but should be corrected.
  2. [Eq. (4.60)] The equation as typeset is confusing: it equates B_Region-2,B-down/16πM_p^2 with a sum that appears to involve the up-tunneling Region-2 and Region-3 terms. Please clarify the notation and ensure the displayed equation matches the sentence that follows.
  3. [Fig. 5] The caption is very long and repeats 'green line' several times; a short schematic or a pointer to the specific panel would improve readability.
  4. [§3.1, Eq. (3.13)] The phrase 'with a presumably missing G on the r.h.s.' in reference [29] is unclear. If this is a comment on the literature, it belongs in a footnote or should be expanded; otherwise it distracts from the main argument.

Circularity Check

1 steps flagged

Central Hamiltonian/WKB computation is self-contained; only a self-flagged, non-load-bearing 'quick argument' reduces to CDL by construction.

specific steps
  1. other [Sec. 5.2.3, 'Quick argument for the relation to CDL', after Eq. (5.13)]
    "Since we are evaluating the difference in on-shell actions between the bounce and the background, as established above, along the CDL trajectory, we are guaranteed to get the CDL answer. ... we find the slick argument of this subsection not completely convincing; however, the explicit computations of the previous subsection demonstrate that the action is the same."

    This auxiliary argument obtains B = B_CDL by construction: the integrand is declared to be the CDL on-shell action difference along the CDL trajectory, so the CDL exponent is an input rather than an output. The authors themselves immediately qualify the argument as 'slick' and 'not completely convincing'. It is not load-bearing for the central claim: Sec. 4 computes B via explicit integrals (4.38), (4.40), (4.53), (4.60) directly from the WDW/WKB momentum p_R without using B_CDL, and only afterwards identifies the sums with the CDL expressions.

full rationale

The main derivation chain is genuinely self-contained. Starting from the Lorentzian Einstein-Hilbert action (3.1), the paper reduces the system to a single domain-wall variable R, derives the canonical momentum and Hamiltonian constraint (4.24)/(4.47), imposes Im(p_R) ≥ 0 with minimal suppression to select branches, and evaluates B = ∫ 2 Im p_R dR (4.29) by explicit integrals. No continuous parameter is fitted to make B equal B_CDL; the Type-B/up results emerge from the Region-2 contributions (4.40), (4.60) and the algebraic identities leading to (4.41), (4.61), (4.62), (4.64). No self-citation is load-bearing: [76] for noncanonical WKB and [73] for uniqueness of umbilic surfaces are external, and the authors' own prior work ([45], [47], [61]) is used only for motivation or context. The only circular-looking passage is the 'quick argument' of Sec. 5.2.3, which the paper itself flags as not completely convincing and which is explicitly secondary to the explicit Sec. 4 computation. The WKB-endpoint concerns at R = 1/H (branch point, divergent Re p_R, discontinuous Im p_R; admitted in Sec. 4.2.2) are a correctness/validity risk rather than circularity, since no CDL value is fed into the calculation that produces that endpoint.

Axiom & Free-Parameter Ledger

1 free parameters · 6 axioms · 1 invented entities

The paper's central claim rests on a standard thin-wall dS junction setup plus several modeling choices that are reasonable but not independently verified: fixed late-time background, Hamiltonian constraint replacing full quantum gravity, noncanonical WKB, and hand-selected branch windings. No continuous constants are fitted to data; the only hand-chosen discrete input is the branch-winding n = 1, which sets the sheet shifts in Tables 1 and 2.

free parameters (1)
  • Branch-winding number n around s = -1 = 1
    Integer sheet-transition choice for arctanh(s) in §4.2.2 and Appendix A; selected by demanding Im(p_R) > 0 with the smallest suppression. It controls the δ = π contributions and therefore the Region-2 part of B. Not fitted to data, but hand-chosen and load-bearing for the Type-B/up results.
axioms (6)
  • domain assumption The thin-wall, pure-tension Israel junction conditions (3.4) describe the domain wall; σ is constant across the wall.
    Used throughout §3–4; ignores wall thickness, back-reaction of matter fields, and possible instability of the wall. The Larfors–Johnson section later acknowledges that real string-theory walls are not pure-tension objects.
  • domain assumption At late times the parent de Sitter is a fixed, non-quantized background; only the domain-wall radius R is dynamical.
    §4.1 explicitly drops scale-factor fluctuations, justified by the large spatial sphere. The central tunneling-rate claim depends on this fixed-background reduction.
  • domain assumption The Hamiltonian constraint H = 0, obtained by varying the lapse, is taken as the defining equation after quantization.
    §4.1: 'We will simply declare this to be the defining equation of our system.' Complete gauge fixing before quantization is later listed by the authors as an open question in §6.
  • domain assumption The WKB formula B = ∫ 2 Im p_R dR is valid for the noncanonical Hamiltonian (4.24)/(4.47).
    Invoked in §4.2.1 with citation [76]; no proof is given in the paper, and the authors admit WKB breaks down near R = 1/H in §4.2.2.
  • domain assumption All SO(3)-symmetric pure-tension domain-wall trajectories in de Sitter are CDL trajectories up to de Sitter isometries.
    Used in §3.1, based on the umbilic-surface classification of [73]. If false, the claimed uniqueness of the large-R on-shell trajectory fails and the relation to CDL is weakened.
  • domain assumption Branch choices and winding numbers in the complex momentum plane may be fixed by the physical condition Im(p_R) ≥ 0 with minimal suppression.
    §4.2.2 and Appendix A; this selects n = 1 and the δ_s, δ_A entries in Tables 1 and 2. It is the main place where the final exponent could in principle be adjusted.
invented entities (1)
  • Quantum-created brane–anti-brane pair of ETW branes near the de Sitter horizon no independent evidence
    purpose: Speculative microphysical picture of the Type-B tunneling trajectory: one brane quantum-jumps outside the horizon while the other contracts to zero size.
    Introduced in §5.2.4 with the explicit caveat that it 'could also turn out to be a subleading process'; no falsifiable prediction or independent observable handle is provided.

pith-pipeline@v1.3.0-alltime-deepseek · 42337 in / 15749 out tokens · 180355 ms · 2026-08-04T01:08:27.006182+00:00 · methodology

0 comments
read the original abstract

It is widely believed that Coleman--De Luccia (CDL) instantons characterize tunneling transitions in a de Sitter multiverse. Their most naive interpretation uses analytic continuation to Lorentzian de Sitter at the minimal size of the spatial three-sphere. However, what one really wants is a geometry where a small bubble of new vacuum forms within the huge spatial sphere of an old parent de Sitter. Even by applying de Sitter isometries to the original CDL solutions, this cannot in general be achieved. In particular, it fails in the gravity-dominated regime, i.e. for up-tunneling and for transitions with heavy domain walls. These cases remain pathological in that the whole multiverse is in the causal future of every single up-tunneling event. To solve this problem, we develop a Hamiltonian description of how a small off-shell bubble grows and eventually goes on shell within the large spatial sphere of late-time de Sitter. We provide the corresponding WKB analysis, recovering the CDL rate. We explain that our tunneling process and that of CDL are described by two different analytic continuations of a unique on-shell trajectory in the Hamiltonian treatment. Our analysis has crucial implications for the Larfors--Johnson problem, which questions the standard mechanism for populating the string-theoretic flux landscape on the basis of an instability of the relevant domain walls.

Figures

Figures reproduced from arXiv: 2608.00159 by Arthur Hebecker, Ben Freivogel, Bjoern Hassfeld, Thibaut Coudarchet.

Figure 1
Figure 1. Figure 1: The Type–A and Type–B Euclidean instantons describing dS–to–dS transitions [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Penrose diagrams of dS tunneling events of Type–A (left) and Type–B (right). [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: The Type–A and Type–B Euclidean instantons and their Lorentzian continua [PITH_FULL_IMAGE:figures/full_fig_p011_3.png] view at source ↗
Figure 5
Figure 5. Figure 5: For the Type–A situation (left), this now leads to a presumably highly suppressed [PITH_FULL_IMAGE:figures/full_fig_p012_5.png] view at source ↗
Figure 4
Figure 4. Figure 4: On the left: Negatively boosted CDL solution for Type–A, such that nucleation [PITH_FULL_IMAGE:figures/full_fig_p013_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: On the top left: Positively boosted CDL solution for Type–A. Like for Type–B [PITH_FULL_IMAGE:figures/full_fig_p014_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Boosted trajectories (3.17) for different values of [PITH_FULL_IMAGE:figures/full_fig_p019_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: The wall radius R as a function of the conformal time T for positive rapidities (left panel) and negative rapidities (right panel). In both plots, the red curve corresponds to the unboosted solution and H has been set to unity. at time t0, determined by sinh(Ht0) = −w sinh(η). (3.22) For bubble-of-nothing solutions, the same expressions apply. While w is still defined as in (3.11), the minimal radius Rcrit… view at source ↗
Figure 7
Figure 7. Figure 7: We note that for up-tunneling transitions, the situation is the same as in the Type–B down-tunneling case described above. The minimal bubble that can nucleate at late times is the size of one Hubble patch of the parent dS. 4 Decay rates Now that we have understood the structure of all possible Lorentzian domain wall trajec￾tories, we turn to late-time decay rates. As explained in Sect. 2, we expect to rec… view at source ↗
Figure 8
Figure 8. Figure 8: Numerical example of the behavior of s− (Mp = 1, H = 1/2 and σ = ±1). On the left: s− for R ≥ Rcrit where it is purely real. The blue curve is Type–A while the red curve is Type–B. On the right: Motion of s− in the complex plane as R goes from large values to small values. Again the blue curve is Type–A and starts at the blue dot, while the red curve is Type–B and starts at the red dot. The arrows show the… view at source ↗
Figure 9
Figure 9. Figure 9: On the left: Real (in blue) and imaginary (in orange) parts of [PITH_FULL_IMAGE:figures/full_fig_p031_9.png] view at source ↗
Figure 10
Figure 10. Figure 10: Left: Maximally boosted CDL geometry where [PITH_FULL_IMAGE:figures/full_fig_p032_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: Real part (in blue) and imaginary part (in orange) of [PITH_FULL_IMAGE:figures/full_fig_p039_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: Two disconnected contributions to the path integral with the past and future [PITH_FULL_IMAGE:figures/full_fig_p041_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: The red curves show unboosted Type–A (left) and Type–B (right) CDL tra [PITH_FULL_IMAGE:figures/full_fig_p043_13.png] view at source ↗
Figure 13
Figure 13. Figure 13: If we allow ourselves to leave this chart, analytically continuing to the patch [PITH_FULL_IMAGE:figures/full_fig_p044_13.png] view at source ↗
Figure 13
Figure 13. Figure 13: • Since we are evaluating the difference in on-shell actions between the bounce and the background, as established above, along the CDL trajectory, we are guaranteed 47 [PITH_FULL_IMAGE:figures/full_fig_p047_13.png] view at source ↗
Figure 13
Figure 13. Figure 13: Due to the presence of the quantum fluctuation, this description seems to have [PITH_FULL_IMAGE:figures/full_fig_p048_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: An attempt to illustrate the complex geometry of our tunneling calculation. [PITH_FULL_IMAGE:figures/full_fig_p049_14.png] view at source ↗
Figure 15
Figure 15. Figure 15: A typical potential with a dS metastable minimum and a runaway region, [PITH_FULL_IMAGE:figures/full_fig_p052_15.png] view at source ↗
Figure 16
Figure 16. Figure 16: Equivalent descriptions for the decay of a domain wall. On the left: A brane [PITH_FULL_IMAGE:figures/full_fig_p053_16.png] view at source ↗

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Reference graph

Works this paper leans on

104 extracted references · 72 linked inside Pith

  1. [1]

    Anthropic Bound on the Cosmological Constant,

    S. Weinberg, “Anthropic Bound on the Cosmological Constant,”Phys. Rev. Lett. 59(1987) 2607

  2. [2]

    Stationary universe,

    A. D. Linde and A. Mezhlumian, “Stationary universe,”Phys. Lett. B307(1993) 25–33,arXiv:gr-qc/9304015

  3. [3]

    A Measure of the multiverse,

    A. Vilenkin, “A Measure of the multiverse,”J. Phys. A40(2007) 6777, arXiv:hep-th/0609193

  4. [4]

    Making predictions in the multiverse,

    B. Freivogel, “Making predictions in the multiverse,”Class. Quant. Grav.28 (2011) 204007,arXiv:1105.0244 [hep-th]

  5. [5]

    Quantization of four form fluxes and dynamical neutralization of the cosmological constant,

    R. Bousso and J. Polchinski, “Quantization of four form fluxes and dynamical neutralization of the cosmological constant,”JHEP06(2000) 006, arXiv:hep-th/0004134

  6. [6]

    The Anthropic landscape of string theory,

    L. Susskind, “The Anthropic landscape of string theory,”arXiv:hep-th/0302219

  7. [7]

    Distributions of flux vacua,

    F. Denef and M. R. Douglas, “Distributions of flux vacua,”JHEP05(2004) 072, arXiv:hep-th/0404116

  8. [8]

    L. E. Ibanez and A. M. Uranga,String theory and particle physics: An introduction to string phenomenology. Cambridge University Press, 2, 2012

  9. [9]

    Lectures on constructing string vacua,

    F. Denef, “Lectures on constructing string vacua,”Les Houches87(2008) 483–610,arXiv:0803.1194 [hep-th]

  10. [10]

    The String Theory Landscape,

    A. N. Schellekens, “The String Theory Landscape,”Adv. Ser. Direct. High Energy Phys.22(2015) 155–217

  11. [11]

    Hebecker,Naturalness, String Landscape and Multiverse: A Modern Introduction with Exercises, vol

    A. Hebecker,Naturalness, String Landscape and Multiverse: A Modern Introduction with Exercises, vol. 979. Springer Cham, 3, 2021.arXiv:2008.10625 [hep-th]

  12. [12]

    Creation of Universes from Nothing,

    A. Vilenkin, “Creation of Universes from Nothing,”Phys. Lett. B117(1982) 25–28

  13. [13]

    Wave Function of the Universe,

    J. B. Hartle and S. W. Hawking, “Wave Function of the Universe,”Phys. Rev. D 28(1983) 2960–2975

  14. [14]

    Quantum Creation of the Inflationary Universe,

    A. D. Linde, “Quantum Creation of the Inflationary Universe,”Lett. Nuovo Cim. 39(1984) 401–405. 62

  15. [15]

    Quantum Creation of Universes,

    A. Vilenkin, “Quantum Creation of Universes,”Phys. Rev. D30(1984) 509–511

  16. [16]

    The Fate of the False Vacuum. 1. Semiclassical Theory,

    S. R. Coleman, “The Fate of the False Vacuum. 1. Semiclassical Theory,”Phys. Rev. D15(1977) 2929–2936. [Erratum: Phys.Rev.D 16, 1248 (1977)]

  17. [17]

    The Fate of the False Vacuum. 2. First Quantum Corrections,

    C. G. Callan, Jr. and S. R. Coleman, “The Fate of the False Vacuum. 2. First Quantum Corrections,”Phys. Rev. D16(1977) 1762–1768

  18. [18]

    Gravitational Effects on and of Vacuum Decay,

    S. R. Coleman and F. De Luccia, “Gravitational Effects on and of Vacuum Decay,”Phys. Rev. D21(1980) 3305

  19. [19]

    Gravity, the Decay of the False Vacuum and the New Inflationary Universe Scenario,

    S. J. Parke, “Gravity, the Decay of the False Vacuum and the New Inflationary Universe Scenario,”Phys. Lett. B121(1983) 313–315

  20. [20]

    Neutralization of the Cosmological Constant by Membrane Creation,

    J. D. Brown and C. Teitelboim, “Neutralization of the Cosmological Constant by Membrane Creation,”Nucl. Phys. B297(1988) 787–836

  21. [21]

    A unified system for Coleman–De Luccia transitions,

    K. Eckerle, “A unified system for Coleman–De Luccia transitions,”Annals Phys. 424(2021) 168362,arXiv:2003.04365 [hep-th]

  22. [22]

    TUNNELING TRANSITIONS WITH GRAVITATION: BREAKING OF THE QUASICLASSICAL APPROXIMATION,

    G. V. Lavrelashvili, V. A. Rubakov, and P. G. Tinyakov, “TUNNELING TRANSITIONS WITH GRAVITATION: BREAKING OF THE QUASICLASSICAL APPROXIMATION,”Phys. Lett. B161(1985) 280–284

  23. [23]

    The Dynamics of False Vacuum Bubbles,

    S. K. Blau, E. I. Guendelman, and A. H. Guth, “The Dynamics of False Vacuum Bubbles,”Phys. Rev. D35(1987) 1747

  24. [24]

    Dynamics of Bubbles in General Relativity,

    V. A. Berezin, V. A. Kuzmin, and I. I. Tkachev, “Dynamics of Bubbles in General Relativity,”Phys. Rev. D36(1987) 2919

  25. [25]

    On the Quantum Mechanics of Bubbles,

    V. A. Berezin, N. G. Kozimirov, V. A. Kuzmin, and I. I. Tkachev, “On the Quantum Mechanics of Bubbles,”Phys. Lett. B212(1988) 415–417

  26. [26]

    Quantum Nucleation of False Vacuum Bubbles,

    W. Fischler, D. Morgan, and J. Polchinski, “Quantum Nucleation of False Vacuum Bubbles,”Phys. Rev. D41(1990) 2638

  27. [27]

    Quantization of False Vacuum Bubbles: A Hamiltonian Treatment of Gravitational Tunneling,

    W. Fischler, D. Morgan, and J. Polchinski, “Quantization of False Vacuum Bubbles: A Hamiltonian Treatment of Gravitational Tunneling,”Phys. Rev. D42 (1990) 4042–4055

  28. [28]

    Quantum Transitions Between Minkowski and de Sitter Spacetimes,

    S. P. De Alwis, F. Muia, V. Pasquarella, and F. Quevedo, “Quantum Transitions Between Minkowski and de Sitter Spacetimes,”Fortsch. Phys.68no. 9, (2020) 2000069,arXiv:1909.01975 [hep-th]. 63

  29. [29]

    Lorentzian vacuum transitions: Open or closed universes?,

    S. Cespedes, S. P. de Alwis, F. Muia, and F. Quevedo, “Lorentzian vacuum transitions: Open or closed universes?,”Phys. Rev. D104no. 2, (2021) 026013, arXiv:2011.13936 [hep-th]

  30. [30]

    Quantum transitions, detailed balance, black holes, and nothingness,

    S. Cespedes, S. de Alwis, F. Muia, and F. Quevedo, “Quantum transitions, detailed balance, black holes, and nothingness,”Phys. Rev. D109no. 10, (2024) 105027,arXiv:2307.13614 [hep-th]

  31. [31]

    Supercooled Phase Transitions in the Very Early Universe,

    S. W. Hawking and I. G. Moss, “Supercooled Phase Transitions in the Very Early Universe,”Phys. Lett. B110(1982) 35–38

  32. [32]

    Is It Possible to Create a Universe in the Laboratory by Quantum Tunneling?,

    E. Farhi, A. H. Guth, and J. Guven, “Is It Possible to Create a Universe in the Laboratory by Quantum Tunneling?,”Nucl. Phys. B339(1990) 417–490

  33. [33]

    A Fresh Look at the Calculation of Tunneling Actions,

    J. R. Espinosa, “A Fresh Look at the Calculation of Tunneling Actions,”JCAP07 (2018) 036,arXiv:1805.03680 [hep-th]

  34. [34]

    From the Big Bang theory to the theory of a stationary universe,

    A. D. Linde, D. A. Linde, and A. Mezhlumian, “From the Big Bang theory to the theory of a stationary universe,”Phys. Rev. D49(1994) 1783–1826, arXiv:gr-qc/9306035

  35. [35]

    Predicting the cosmological constant with the scale-factor cutoff measure,

    A. De Simone, A. H. Guth, M. P. Salem, and A. Vilenkin, “Predicting the cosmological constant with the scale-factor cutoff measure,”Phys. Rev. D78 (2008) 063520,arXiv:0805.2173 [hep-th]

  36. [36]

    Holographic probabilities in eternal inflation,

    R. Bousso, “Holographic probabilities in eternal inflation,”Phys. Rev. Lett.97 (2006) 191302,arXiv:hep-th/0605263

  37. [37]

    Properties of the scale factor measure,

    R. Bousso, B. Freivogel, and I.-S. Yang, “Properties of the scale factor measure,” Phys. Rev. D79(2009) 063513,arXiv:0808.3770 [hep-th]

  38. [38]

    Holographic No-Boundary Measure,

    T. Hertog and J. Hartle, “Holographic No-Boundary Measure,”JHEP05(2012) 095,arXiv:1111.6090 [hep-th]

  39. [39]

    The Static Quantum Multiverse,

    Y. Nomura, “The Static Quantum Multiverse,”Phys. Rev. D86(2012) 083505, arXiv:1205.5550 [hep-th]

  40. [40]

    Tensor modes on the string theory landscape,

    A. Westphal, “Tensor modes on the string theory landscape,”JHEP04(2013) 054,arXiv:1206.4034 [hep-th]

  41. [41]

    The Scale of Inflation in the Landscape,

    F. G. Pedro and A. Westphal, “The Scale of Inflation in the Landscape,”Phys. Lett. B739(2014) 439–444,arXiv:1303.3224 [hep-th]

  42. [42]

    One Bubble to Rule Them All,

    J. Hartle and T. Hertog, “One Bubble to Rule Them All,”Phys. Rev. D95no. 12, (2017) 123502,arXiv:1604.03580 [hep-th]. 64

  43. [43]

    Computational complexity of the landscape II—Cosmological considerations,

    F. Denef, M. R. Douglas, B. Greene, and C. Zukowski, “Computational complexity of the landscape II—Cosmological considerations,”Annals Phys.392(2018) 93–127,arXiv:1706.06430 [hep-th]

  44. [44]

    Vacuum Selection from Cosmology on Networks of String Geometries,

    J. Carifio, W. J. Cunningham, J. Halverson, D. Krioukov, C. Long, and B. D. Nelson, “Vacuum Selection from Cosmology on Networks of String Geometries,” Phys. Rev. Lett.121no. 10, (2018) 101602,arXiv:1711.06685 [hep-th]

  45. [45]

    A local Wheeler-DeWitt measure for the string landscape,

    B. Hassfeld, A. Hebecker, M. Salmhofer, J. C. Strauss, and J. Walcher, “A local Wheeler-DeWitt measure for the string landscape,”Nucl. Phys. B992(2023) 116230,arXiv:2205.09772 [hep-th]

  46. [46]

    Bayesian reasoning in eternal inflation: A solution to the measure problem,

    J. Khoury and S. S. C. Wong, “Bayesian reasoning in eternal inflation: A solution to the measure problem,”Phys. Rev. D108no. 2, (2023) 023506, arXiv:2205.11524 [hep-th]

  47. [47]

    End-of-the-world branes and inflationary predictions for rocky and swampy landscapes,

    B. Hassfeld, A. Hebecker, and A. Westphal, “End-of-the-world branes and inflationary predictions for rocky and swampy landscapes,”JHEP03(2025) 196, arXiv:2411.11944 [hep-th]

  48. [48]

    Small Vacuum Energy and Tunneling in a Modified Bousso-Polchinski Model,

    J. Halverson, J. Khoury, and C. Long, “Small Vacuum Energy and Tunneling in a Modified Bousso-Polchinski Model,”arXiv:2605.05357 [hep-th]

  49. [49]

    Recovering the negative mode for type B Coleman–de Luccia instantons,

    I.-S. Yang, “Recovering the negative mode for type B Coleman–de Luccia instantons,”Phys. Rev. D87no. 8, (2013) 084026,arXiv:1210.4740 [hep-th]

  50. [50]

    Quantum decay of domain walls in cosmology. 2: Hamiltonian approach,

    S. J. Kolitch and D. M. Eardley, “Quantum decay of domain walls in cosmology. 2: Hamiltonian approach,”Phys. Rev. D56(1997) 4663–4674, arXiv:gr-qc/9706033

  51. [51]

    Inflation Expels Runaways,

    T. C. Bachlechner, “Inflation Expels Runaways,”JHEP12(2016) 155, arXiv:1608.07576 [hep-th]

  52. [52]

    Instability of the Kaluza-Klein Vacuum,

    E. Witten, “Instability of the Kaluza-Klein Vacuum,”Nucl. Phys. B195(1982) 481–492

  53. [53]

    SOME STABILITY QUESTIONS FOR HIGHER DIMENSIONAL THEORIES,

    R. E. Young, “SOME STABILITY QUESTIONS FOR HIGHER DIMENSIONAL THEORIES,”Phys. Lett. B142(1984) 149–152

  54. [54]

    Nonperturbative Instability of AdS(5) x S**5/Z(k),

    G. T. Horowitz, J. Orgera, and J. Polchinski, “Nonperturbative Instability of AdS(5) x S**5/Z(k),”Phys. Rev. D77(2008) 024004,arXiv:0709.4262 [hep-th]. 65

  55. [55]

    Stretched extra dimensions and bubbles of nothing in a toy model landscape,

    I.-S. Yang, “Stretched extra dimensions and bubbles of nothing in a toy model landscape,”Phys. Rev. D81(2010) 125020,arXiv:0910.1397 [hep-th]

  56. [56]

    Bubbles of Nothing and Supersymmetric Compactifications,

    J. J. Blanco-Pillado, B. Shlaer, K. Sousa, and J. Urrestilla, “Bubbles of Nothing and Supersymmetric Compactifications,”JCAP10(2016) 002,arXiv:1606.03095 [hep-th]

  57. [57]

    Nothing is certain in string compactifications,

    I. García Etxebarria, M. Montero, K. Sousa, and I. Valenzuela, “Nothing is certain in string compactifications,”JHEP12(2020) 032,arXiv:2005.06494 [hep-th]

  58. [58]

    Nothing really matters,

    G. Dibitetto, N. Petri, and M. Schillo, “Nothing really matters,”JHEP08(2020) 040,arXiv:2002.01764 [hep-th]

  59. [59]

    De Sitter decays to infinity,

    P. Draper, I. Garcia Garcia, and B. Lillard, “De Sitter decays to infinity,”JHEP 12(2021) 154,arXiv:2105.10507 [hep-th]

  60. [60]

    Bubbles of nothing: the tunneling potential approach,

    J. J. Blanco-Pillado, J. R. Espinosa, J. Huertas, and K. Sousa, “Bubbles of nothing: the tunneling potential approach,”JCAP03(2024) 029, arXiv:2312.00133 [hep-th]

  61. [61]

    Cobordism and bubbles of anything in the string landscape,

    B. Hassfeld, A. Hebecker, and J. Walcher, “Cobordism and bubbles of anything in the string landscape,”JHEP02(2024) 127,arXiv:2310.06021 [hep-th]

  62. [62]

    Field dynamics and tunneling in a flux landscape,

    M. C. Johnson and M. Larfors, “Field dynamics and tunneling in a flux landscape,”Phys. Rev. D78(2008) 083534,arXiv:0805.3705 [hep-th]

  63. [63]

    An Obstacle to populating the string theory landscape,

    M. C. Johnson and M. Larfors, “An Obstacle to populating the string theory landscape,”Phys. Rev. D78(2008) 123513,arXiv:0809.2604 [hep-th]

  64. [64]

    Runaway dilatonic domain walls,

    A. Aguirre, M. C. Johnson, and M. Larfors, “Runaway dilatonic domain walls,” Phys. Rev. D81(2010) 043527,arXiv:0911.4342 [hep-th]

  65. [65]

    Hawking-Moss bounces and vacuum decay rates,

    E. J. Weinberg, “Hawking-Moss bounces and vacuum decay rates,”Phys. Rev. Lett.98(2007) 251303,arXiv:hep-th/0612146

  66. [66]

    Thermal derivation of the Coleman-De Luccia tunneling prescription,

    A. R. Brown and E. J. Weinberg, “Thermal derivation of the Coleman-De Luccia tunneling prescription,”Phys. Rev. D76(2007) 064003,arXiv:0706.1573 [hep-th]

  67. [67]

    Stochastic Tunneling in de Sitter Spacetime,

    T. Miyachi, J. Soda, and J. Tokuda, “Stochastic Tunneling in de Sitter Spacetime,”Universe10no. 7, (2024) 292,arXiv:2309.07440 [hep-th]

  68. [68]

    Remote Hawking-Moss instanton and the Lorentzian path integral,

    D. Saito and N. Oshita, “Remote Hawking-Moss instanton and the Lorentzian path integral,”JHEP02(2025) 187,arXiv:2409.03978 [hep-th]. 66

  69. [69]

    Supergravity and a confining gauge theory: Duality cascades and chi SB resolution of naked singularities,

    I. R. Klebanov and M. J. Strassler, “Supergravity and a confining gauge theory: Duality cascades and chi SB resolution of naked singularities,”JHEP08(2000) 052,arXiv:hep-th/0007191

  70. [70]

    A Large mass hierarchy from a small extra dimension,

    L. Randall and R. Sundrum, “A Large mass hierarchy from a small extra dimension,”Phys. Rev. Lett.83(1999) 3370–3373,arXiv:hep-ph/9905221

  71. [71]

    Hierarchies from fluxes in string compactifications,

    S. B. Giddings, S. Kachru, and J. Polchinski, “Hierarchies from fluxes in string compactifications,”Phys. Rev. D66(2002) 106006,arXiv:hep-th/0105097

  72. [72]

    The Throat as a Randall-Sundrum model with Goldberger-Wise stabilization,

    F. Brummer, A. Hebecker, and E. Trincherini, “The Throat as a Randall-Sundrum model with Goldberger-Wise stabilization,”Nucl. Phys. B738(2006) 283–305, arXiv:hep-th/0510113

  73. [73]

    Vacuum branes in D-dimensional static space-times with spatial symmetry IO(D-2), O(D-1) or O+(D-2,1),

    H. Kodama, “Vacuum branes in D-dimensional static space-times with spatial symmetry IO(D-2), O(D-1) or O+(D-2,1),”Prog. Theor. Phys.108(2002) 253–295,arXiv:gr-qc/0204042

  74. [74]

    Quantum Theory of Gravity. 1. The Canonical Theory,

    B. S. DeWitt, “Quantum Theory of Gravity. 1. The Canonical Theory,”Phys. Rev. 160(1967) 1113–1148

  75. [75]

    T C P, Quantum Gravity, the Cosmological Constant and All That

    T. Banks, “T C P, Quantum Gravity, the Cosmological Constant and All That...” Nucl. Phys. B249(1985) 332–360

  76. [76]

    WKB approximation and tunneling in theories with noncanonical kinetic terms,

    M. Carrillo González, A. Masoumi, A. R. Solomon, and M. Trodden, “WKB approximation and tunneling in theories with noncanonical kinetic terms,”Phys. Rev. D96no. 5, (2017) 056021,arXiv:1703.00909 [hep-th]

  77. [77]

    Consistent Evaluation of the No-Boundary Proposal,

    A. I. Abdalla, S. Antonini, R. Bousso, L. V. Iliesiu, A. Levine, and A. Shahbazi-Moghaddam, “Consistent Evaluation of the No-Boundary Proposal,” arXiv:2602.02682 [hep-th]

  78. [78]

    Vacuum decay in the Lorentzian path integral,

    T. Hayashi, K. Kamada, N. Oshita, and J. Yokoyama, “Vacuum decay in the Lorentzian path integral,”JCAP05no. 05, (2022) 041,arXiv:2112.09284 [hep-th]

  79. [79]

    Steepest Descent Contours in the Path Integral Approach to Quantum Cosmology. 1. The De Sitter Minisuperspace Model,

    J. J. Halliwell and J. Louko, “Steepest Descent Contours in the Path Integral Approach to Quantum Cosmology. 1. The De Sitter Minisuperspace Model,”Phys. Rev. D39(1989) 2206

  80. [80]

    Steepest Descent Contours in the Path Integral Approach to Quantum Cosmology. 2. Microsuperspace,

    J. J. Halliwell and J. Louko, “Steepest Descent Contours in the Path Integral Approach to Quantum Cosmology. 2. Microsuperspace,”Phys. Rev. D40(1989) 1868. 67

Showing first 80 references.