Large Gravitational Waves and Lyth Bound in Multi Brane Inflation

Axel Krause

RECORD

Large Gravitational Waves and Lyth Bound in Multi Brane Inflation

Axel Krause

High Energy Physics - Theory · Submitted 31 Aug 2007

abstract compiled · 2026-09-23 · no language-model review

The authors' main claim It is shown that multi M5-brane inflation in heterotic M-theory gives rise to a detectable gravitational wave power spectrum with tensor fraction $r$ typically larger than the projected experimental sensitivity, $r_{exp} = 0.01$.

how it is stated · asserted 0.99 read the record →

Comment (0) Read on arXiv ↗

Cite ▾

Claim paper

The compiled record

The paper's own sentences, arranged. 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.

Open the compiled record

Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 3,595 input tokens, $0.0002 reported.

What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.26 · human participants 0.01 · controlled comparison 0.07 · randomized assignment 0.01 · states quantitative result 0.94 · compares with prior results 0.59 · mentions code or data availability 0.01.

The abstract, sentence by sentence

arXiv listing abstract v3. Results and the main claim are underlined; show every role.

It is shown that multi M5-brane inflation in heterotic M-theory gives rise to a detectable gravitational wave power spectrum with tensor fraction $r$ typically larger than the projected experimental sensitivity, $r_{exp} = 0.01$. A measurable gravitational wave power spectrum entails a large inflationary energy scale and a super-Planckian inflaton variation. They present serious problems for particle theory model building resp. a reliable effective field theory description. These problems are eased or even absent in multi-brane inflation models and multi M5-brane inflation, in particular.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#	sentence	role	the authors' own work	states the main conclusion	strength
s0	It is shown that multi M5-brane inflation in heterotic M-theory gives rise to a detectable gravitational wave power spectrum with tensor fraction $r$ typically larger than the projected experimental sensitivity, $r_{exp} = 0.01$.	result 0.98	0.85	0.86	asserted 0.99
s1	A measurable gravitational wave power spectrum entails a large inflationary energy scale and a super-Planckian inflaton variation.	interpretation 0.77	0.28	0.11	asserted 1.00
s2	They present serious problems for particle theory model building resp. a reliable effective field theory description.	background 0.50	0.15	0.08	asserted 1.00
s3	These problems are eased or even absent in multi-brane inflation models and multi M5-brane inflation, in particular.	interpretation 0.79	0.37	0.28	asserted 0.66

What kind of paper the classifier reports this is: theoretical result 1.00 · evidence from proof or derivation 0.90.

What was examined, and what was not

sources read

arXiv listing abstract v3

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

The paper

Original abstract

It is shown that multi M5-brane inflation in heterotic M-theory gives rise to a detectable gravitational wave power spectrum with tensor fraction $r$ typically larger than the projected experimental sensitivity, $r_{exp} = 0.01$. A measurable gravitational wave power spectrum entails a large inflationary energy scale and a super-Planckian inflaton variation. They present serious problems for particle theory model building resp. a reliable effective field theory description. These problems are eased or even absent in multi-brane inflation models and multi M5-brane inflation, in particular.

Human review

How Pith checks papers → · Full audit of this paper →

References

Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

Axion Inflation in Type II String Theory
hep-th 2007-10 conditional novelty 6.0 of 10

Axions from vanishing two-cycles in type IIB compactifications can have near-Planckian decay constants after string world-sheet corrections, potentially enabling multi-field inflation with tensor-to-scalar ratio up to 0.14.
String Cosmology: A Review
hep-th 2007-10 accept novelty 3.0 of 10

String cosmology's central obstacle is the eta problem: moduli stabilization generically generates inflaton mass terms of order the Hubble scale, and no fully explicit, correction-controlled string inflation model yet exists.

How the literature uses it

15 arXiv papers cite this in 15 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 · 9 sentences without a confident label

Cites it as support 1 paper

However, the use of an effective single field is problematic for several reasons; first of all, there is no a priori reason to expect that fields decay (stabilize) all at once; indeed, there are cases, such as in inflation from multiple M5-Branes [ref] , where a coherent decay (stabilization) is impossible [During inflation the M5-branes separate from each other until they encounter a boundary brane into which they dissolve, one after the other.].

Multi-Field Inflation on the Landscape · Introduction · 0.97

Cites it as background 5 papers

This culminated in the multi-brane model of [ref] (supplemented by follow-up work in [ref] ) and other related ideas [ref] .

Higher order corrections to Heterotic M-theory inflation · Introduction · 0.86
More elaborate (though still effectively single-field) models have been considered in order to evade these bounds, involving wrapped branes [ref] or multiple branes [ref] rather than a single D3-brane.

Multi-field DBI inflation: introducing bulk forms and revisiting the gravitational wave constraints · Gravitational wave constraints on DBI inflation · 0.80
Some recent developments on N-flation and multi-brane inflation can be found in [ref] .

Spinflation from Geometric Tachyon · Introduction · 0.99

What it cites · 57 sentences without a confident label

Uses data or values from 6 papers

For instance, for a maximal $N$ of order 200 [ref] one finds, with values for $s$ and $t$ as before, a lower bound $r ≥2.4×10^-3$, which is close to the experimental sensitivity.

M-Theory Inflation from Multi M5-Brane Dynamics · Detectable Gravitational Waves · 0.89
Combining Wilkinson Microwave Anisotropy Probe 3-year (WMAP3) and Sloan Digital Sky Survey (SDSS) data one finds $r<0.31$ and $0.93<n_S<1.01$ in the absence of running and $r<0.38$ together with $0.97<n_S<1.21$ and $-0.13< dn_S/dlnk <0.007$ in the presence of running [ref] (see also [ref] , [ref] , [ref] , [ref] ).

Prospects for direct detection of primordial gravitational waves · Scalar and Tensor Perturbations · 0.95
Combining Wilkinson Microwave Anisotropy Probe 3-year (WMAP3) and Sloan Digital Sky Survey (SDSS) data one finds $r<0.31$ and $0.93<n_S<1.01$ in the absence of running and $r<0.38$ together with $0.97<n_S<1.21$ and $-0.13< dn_S/dlnk <0.007$ in the presence of running [ref] (see also [ref] , [ref] , [ref] , [ref] ).

The Search For Primordial Tensor Modes · Scalar and Tensor Perturbations · 0.95

Compares with 1 paper

In contrast to the ordinary power-law inflation $r$-$n_S$ relation [ref] , multi M5-brane inflation places a lower bound on $r$, which arises as follows.

Direct detection of the inflationary gravitational wave background · Detectable Gravitational Waves · 0.90

Cites as background 15 papers

Since we are interested in the production of gravitational waves from multi M5-brane inflation in heterotic M-theory, let us briefly review its main features (for details the reader is referred to [ref] ).

M-Theory Inflation from Multi M5-Brane Dynamics · Multi M5-Brane Inflation · 0.99
The first is the implied large value of $V$ around the GUT scale, the second is the Lyth bound [ref] .

What would we learn by detecting a gravitational wave signal in the cosmic microwave background anisotropy? · Introduction · 0.89
The gravitational wave power spectrum, $P_T = 100 A_T^2$, [ref] , [ref] is thus suppressed by the small slow-roll parameter $ϵ$ compared to the scalar power spectrum, $P_S = (25/4) A_S^2$ [ref] , [ref] .

A more accurate analytic calculation of the spectrum of cosmological perturbations produced during inflation · Scalar and Tensor Perturbations · 0.93

Discussion

Know something about this paper? Leave a comment, or highlight any passage above to comment on it.