Pith. Sign in

REVIEW

Saltatory Relaxation of the Cosmological Constant

High Energy Physics - Theory · Submitted 30 May 2000 · 41 references

Pith's verdict: Two genuinely new string-theoretic ingredients for Brown-Teitelboim relaxation, wrapped around a headline relation that is conditional on an assumption the authors themselves flag.

T0 · AI review

How this review was made: An AI referee (selfhosted/deepseek-v4.1-flash) read the paper on November 11, 2026 and answered a fixed list of questions about it. T0 is the starting level every paper gets. The levels describe how deeply Pith has checked the paper, never the authors.

  1. T0 AI review An AI read the paper and answered a fixed list of questions.
  2. T1 Audit Automatic checks that the references and files the paper relies on exist and match.
  3. T2 Compute The paper's code or calculations re-run with the same results.
  4. T3 Formal statement The claims written out in a formal math language a computer can read.
  5. T4 Proof Those claims proved, and the proof checked by computer.

How Pith checks papers →

· 5 major objections · 8 minor · Ask about this paper · The compiled record · Read the full review →
Challenge this review Comment (0) Read on arXiv ↗
Cite ▾
arXiv IDhep-th/0005276 (version 2)
Pith IDMPDZZ6AV, Pith's permanent record of this paper and its review
CitationFrank Wilczek, John March-Russell, Jonathan L. Feng, Savdeep Sethi. "Saltatory Relaxation of the Cosmological Constant." arXiv:hep-th/0005276 (2000). https://pith.science/paper/MPDZZ6AV
Cite this reviewBibTeX for Pith's review of this paper
Claim paper

Why Pith says this

Highlight any text to comment on it.

Referee report
The paper

The paper claims

String/M-theory brane properties and coincident-brane density of states can make saltatory relaxation of the cosmological constant fast enough, and requiring stability on cosmological timescales then implies a supersymmetry breaking scale below a few TeV.

The reading

The cosmological constant problem asks why the vacuum energy of the universe is some 120 orders of magnitude smaller than naive theoretical estimates. Brown and Teitelboim proposed that the vacuum energy relaxes in discrete jumps as membranes nucleate, each jump reducing the effective cosmological term by a quantized amount. The problem was that the required jump size is absurdly small, and the tunneling rate is exponentially suppressed. This paper argues that string/M-theory naturally supplies both fixes. First, the charge and tension of branes depend on the size and shape of extra dimensions, so the effective four-dimensional jump size can be exponentially small without fine-tuning fundamental parameters. Second, when many branes nucleate together, their internal degrees of freedom contribute a large density-of-states factor that can overcome the tunneling suppression. With these ingredients, the authors study whether the vacuum can relax to the observed value and then stay there. They find that requiring stability on cosmological timescales, rather than absolute stability, yields a relation: the supersymmetry breaking scale must be below about a few TeV. This is a conditional statement, resting on the assumption that the bare cosmological constant is set by the supersymmetry breaking scale. The authors are explicit that the work is incomplete: no realistic cosmological model with matter is constructed, and the temperature controlling the density-of-states factor is not under theoretical control.
Extended reading notes

Core claim

The central load-bearing assertion is Eq. (47): requiring that the effective cosmological term be stable on cosmological timescales, rather than absolutely stable, yields the relation M_SUSY^2 less than about (10^-3 eV)(M_Planck), equivalently a supersymmetry breaking scale below a few TeV. If correct, this connects the observed cosmological constant, the Planck scale, and the scale of supersymmetry breaking in a single inequality, and it makes the saltatory relaxation mechanism testable at colliders.

Load-bearing premise

The load-bearing premise is the identification of the bare cosmological constant with the supersymmetry breaking scale, Eq. (41): lambda M^2 ~ M_SUSY^4. The authors justify it only by saying it is 'reasonable to expect' (Sec. 5.1). If the bare cosmological term is instead set by a hidden sector at a much higher scale, the stability bound B > 1 fails and the vacuum is unstable in the simplest scenario. The authors acknowledge this explicitly: 'Unless the hidden sector contribution to the bare cosmological term is somehow suppressed to this TeV scale, in our simplest scenario the vacuum will be unstable.'

Original abstract

We modify and extend an earlier proposal by Brown and Teitelboim to relax the effective cosmological term by nucleation of branes coupled to a three-index gauge potential. Microscopic considerations from string/M theory suggest two major innovations in the framework. First, the dependence of brane properties on the compactification of extra dimensions may generate a very small quantized unit for jumps in the effective cosmological term. Second, internal degrees of freedom for multiply coincident branes may enhance tunneling rates by exponentially large density of states factors. These new features essentially alter the relaxation dynamics. By requiring stability on the scale of the lifetime of the universe, rather than absolute stability, we derive a non-trivial relation between the supersymmetry breaking scale and the value of the cosmological term. It is plausibly, though not certainly, satisfied in Nature.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 5,492 input tokens, $0.0002 reported.

What the abstract itself states, as probabilities: claims first 0.04 · states limitation 0.87 · human participants 0.01 · controlled comparison 0.03 · randomized assignment 0.01 · states quantitative result 0.11 · compares with prior results 0.67 · mentions code or data availability 0.01.

The abstract, sentence by sentence

arXiv listing abstract v2. Results and the main claim are underlined; .

We modify and extend an earlier proposal by Brown and Teitelboim to relax the effective cosmological term by nucleation of branes coupled to a three-index gauge potential. Microscopic considerations from string/M theory suggest two major innovations in the framework. First, the dependence of brane properties on the compactification of extra dimensions may generate a very small quantized unit for jumps in the effective cosmological term. Second, internal degrees of freedom for multiply coincident branes may enhance tunneling rates by exponentially large density of states factors. These new features essentially alter the relaxation dynamics. By requiring stability on the scale of the lifetime of the universe, rather than absolute stability, we derive a non-trivial relation between the supersymmetry breaking scale and the value of the cosmological term. It is plausibly, though not certainly, satisfied in Nature.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 We modify and extend an earlier proposal by Brown and Teitelboim to relax the effective cosmological term by nucleation of branes coupled to a three-index gauge potential. contribution 0.98 0.88 0.08 asserted 0.99
s1 Microscopic considerations from string/M theory suggest two major innovations in the framework. contribution 0.86 0.18 0.03 hedged possibility 0.86
s2 First, the dependence of brane properties on the compactification of extra dimensions may generate a very small quantized unit for jumps in the effective cosmological term. contribution 0.92 0.21 0.07 hedged possibility 1.00
s3 Second, internal degrees of freedom for multiply coincident branes may enhance tunneling rates by exponentially large density of states factors. contribution 0.96 0.21 0.06 hedged possibility 0.99
s4 These new features essentially alter the relaxation dynamics. interpretation 0.88 0.53 0.09 asserted 0.98
s5 By requiring stability on the scale of the lifetime of the universe, rather than absolute stability, we derive a non-trivial relation between the supersymmetry breaking scale and the value of the cosmological term. result 0.92 0.93 0.62 asserted 1.00
s6 It is plausibly, though not certainly, satisfied in Nature. interpretation 0.84 0.39 0.11 hedged possibility 0.99

What kind of paper the classifier reports this is: theoretical result 1.00 · evidence from argument 0.59.

What was examined, and what was not

sources read
  • arXiv listing abstract v2
not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
levels run
  • P abstract
not run
  • S sections
  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

References
How the literature uses it

45 arXiv papers cite this in 56 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers citing it · 32 sentences without a confident label

Contests it 1 paper
Builds on it 1 paper
Uses its method or tool 1 paper
Compares with it 4 papers
Cites it as background 17 papers

Discussion

Disagree with the review, or know something it missed? Leave a comment, highlight any passage above to comment on it, or challenge this review formally.