You said:
ChatGPT said:
I reviewed the uploaded PDF/TeX draft; line numbers below refer to 1.tex.
A. Must-fix items before circulation/submission
-
Active internal comments are still in the manuscript.
Locations: lines 184–186; line 445; line 1412.
Context:
\wqy{I think we can name the paper as ...}
\dgw{TBD}
Fig. 1 caption contains DGW/WQY discussion comments.
We would like to thank ... for helpful discussions.
Fix: remove all author comments and replace the acknowledgement placeholder. -
Massless mode function has the wrong power of H.
2k3H2(1+ikη)e−ikη.
Location: Eq. (1.7), line 320.
Current:Issue: for a canonically normalized massless scalar in dS, this should be H/2k3, not H2/2k3. The current expression makes later powers of H inconsistent.
uk(η)=2k3H(1+ikη)e−ikη.
Fix: -
Schwinger–Keldysh bulk-to-bulk Green-function identity is missing the branch sign.
(□η−m2)Dbc(k,η,η′)=i(−Hη)4δ(η−η′)δbc.
Location: Eq. (1.8), line 331.
Current:Issue: later in the paper, for example around Eq. (3.6), you use the branch-dependent sign ib.
(□η−m2)Dbc(k,η,η′)=ib(−Hη)4δ(η−η′)δbc,
Fix:assuming b=± is identified with ±1.
-
The general action in Eq. (1.2) does not match the stated class of theories.
S=∫d4x−g[i∑(−21(∂Φi)2−21mi2Φi2)+Lint(Φi,∇μΦi,…)].
Location: lines 270–272.
Current text: “general interactions involving only first time derivatives of the fields.”
Issue: Eq. (1.2) contains only a potential V[Φi], while later sections use derivative interactions, higher-derivative interactions, and boost-breaking operators.
Fix: either restrict the sentence or write the action as something likeThen state separately which derivative order is assumed in Sec. 2.
-
Principal/complementary mass thresholds are written dimensionally incorrectly.
mσ=m>23H,mσ=m<23H.
Locations: lines 279, 284, 247, 255.
Current: m>3H/2 is rendered in several places asm > 3H 2; similarly for m<3H/2.
Fix: write explicitlyIn the TeX, use
m > 3H/2orm>\frac{3H}{2}. -
Sec. 3 says the direct boundary differential-equation validation is in Appendix A, but Appendix A is about path-integral issues.
Location: line 564.
Current: “a procedure we rigorously perform in Appendix A for validation.”
Fix: this should probably be Appendix B, or Appendix B/C depending on the intended reference. -
Fig. 1 caption contains a substantive definition error for Eint.
Eint=−g(ϕϕ′′+21(ϕ′)2)
Location: line 444.
Current:
Eint=−λg(ϕ3ϕ′′+21ϕ2(ϕ′)2) “is the interaction part of the equation of motion.”
Issue: the factor λ comes from f=λϕ2, so the displayed object is closer to Eintf, not Eint.
Fix: either writefor the example, and then separately Eintf=−λg(⋯), or relabel the caption as “Eintf=⋯.”
-
Fig. 1 caption also has several obvious text bugs.
Location: line 444.
Current: “Blue sots”; “E0=(∂2−m2)ϕ”; author comments remain.
Fix: “Blue dots”; use E0=(□−m2)ϕ; delete all comments. -
Eq. (3.21) uses a different normalization for the cubic derivative interaction than Sec. 3.1.
Locations: line 764 versus lines 576, 588, 607, etc.
Issue: Sec. 3.1 repeatedly uses 21λ3(∇ϕ)2σ, but Eq. (3.21) writes λ3(∇ϕ)2σ. This can shift factors of 2 in the field-redefinition discussion.
Fix: use one convention throughout, or explicitly state that the λ3 in Sec. 3.2 differs by a factor of 2. -
The field-redefinition expansion in Eq. (3.23) should be checked for signs and factors after fixing the normalization above.
−2λ3∇σ∇(ϕ~2),λ2λ3(ϕ~˙σ2+ϕ~σσ˙)
Location: line 773.
Issue: because the original interaction normalization is inconsistent, the induced termsmay not match the intended λ3.
Fix: redo this short expansion after choosing the convention for λ3. -
Eq. (3.33) appears to miss a curvature-commutator term.
∫−g(∇μ∇νϕ)2σ=−∫−g(∇μϕ)(∇μ□ϕ)σ+21∫−g(∇μϕ)2□σ.
Location: line 853.
Current identity:Issue: in curved space, commuting covariant derivatives acting on ∇μϕ produces a Ricci term. One expects a contribution proportional to
−∫−gσRμν∇μϕ∇νϕ,which in dS4 is −3H2∫−gσ(∇ϕ)2.
Fix: either add the curvature term and propagate it into the recursion relations, or state clearly that ∇nϕ in Sec. 3.3 is a schematic/ordinary-derivative operator for which this commutator is not included. -
The recursion relations in Sec. 3.3 may be affected by the missing curvature term.
Locations: Eqs. (3.34)–(3.39), lines 862–899.
Issue: if the covariant-derivative identity is corrected, extra lower-derivative exchange/contact terms proportional to H2 should appear.
Fix: rederive the recursion after deciding whether ∇nϕ denotes genuinely covariant derivatives or a shorthand basis modulo curvature terms. -
Eq. (4.1) has index typos in the most general boost-breaking operator.
∂k1⋯∂kγ3∂l1⋯∂jγ1σ.
Location: lines 974–980.
Issue: the third factor for σ contains repeated/mismatched indices:The k-indices should pair with γ2, and the final jγ1 should be lγ1.
(∂ηα3(∂i2)β3∂k1⋯∂kγ2∂l1⋯∂lγ1σ).
Fix: use something like -
Massive-field EOM sign in Eq. (4.5) is likely wrong.
cσ2k2σ=−∂η2σ+η2∂ησ+H2η2m2σ.
Location: line 999.
Current:Issue: for
σ′′−η2σ′+(cσ2k2+H2η2m2)σ=0,solving for cσ2k2σ gives a minus mass term.
cσ2k2σ=−σ′′+η2σ′−H2η2m2σ.
Fix: -
Eq. (4.6) has multiple notation/sign problems.
(4−α123′)H(−Hη)α123′−5
Location: lines 1001–1008.
Issues:
a'_{123}appears where α123′ is intended; powers switch between (−Hη) and (Hη); the sign of the derivative of the measure factor should be checked.
Fix: rewrite the formula cleanly. For example, after IBP one expects a term proportional toup to the chosen sign convention, plus the two terms where one derivative is moved from σ to the two ϕ’s.
-
Undefined/misleading ks notation in Sec. 4.1.
Locations: lines 1013 and 1059.
Current: “internal powers ks2m” / “powers ks2.”
Issue: ks is not defined; the internal momentum magnitude is denoted s.
Fix: replace by s2m, s2, or “powers of the internal momentum magnitude s.” -
The Schwinger–Keldysh sewing condition under field redefinitions is oversimplified.
Φ+(η0)+f[Φ+](η0)=Φ−(η0)+f[Φ−](η0),
Location: Appendix A, Eq. (A.1), lines 1421–1430.
Issue: after Φ=Φ~+f[Φ~], the final-time condition should transform asnot simply Φ+(η0)=Φ−(η0), unless the redefinition is derivative-free and invertible pointwise on the boundary. This is especially important because Sec. 4.2 later discusses velocity-dependent redefinitions.
Fix: restrict Appendix A explicitly to derivative-independent local field redefinitions, or formulate the derivation in phase space/canonical variables. -
The Jacobian formula in Eq. (A.2) is mathematically misleading.
exp[∫d4xlog[1+f′[Φ(x)]δ(4)(x−x)]].
Location: lines 1438–1440.
Current:Issue: the δ(0) comes from the trace, not inside the logarithm in this way.
lnJ=Trln[(1+f′(Φ(x)))δ(4)(x−y)]=δ(4)(0)∫d4xln(1+f′(Φ(x))).
Fix: for derivative-free f, writeAlso fix the extra parenthesis in the displayed expression.
-
The dimensional-regularization statement about δ(d)(0) is inaccurate.
Location: line 1447.
Current: “In dimensional regularization, terms proportional to δ(d)(0) and its derivatives are divergent as 1/ϵ.”
Issue: in dim reg, scaleless contact quantities such as δ(d)(0)=∫ddp/(2π)d are often set to zero; more generally they represent local UV counterterms.
Fix: say “Such terms are local UV contact terms; in dimensional regularization scaleless ones vanish, and in other schemes they can be absorbed into local counterterms.” -
Broken-phase field redefinition omits the identity term.
ΔΦ→f[ΔΦ~+Φˉ]−f[Φˉ].
Location: Eq. (A.9), line 1498.
Current:Issue: this maps the fluctuation only to the nonlinear part, not to itself plus the nonlinear shift.
ΔΦ=ΔΦ~+f[Φˉ+ΔΦ~]−f[Φˉ].
Fix: -
Contradiction in the second-order Schwinger–Dyson discussion.
Δr2S=−2ΔrΔaS,
Locations: lines 1573 and 1598.
Current: line 1573 saysbut line 1598 says they are equal.
21Δr2S+ΔrΔaS=0,
Fix: the cancellation should be described aswith the factors appearing in Eq. (A.20).
-
Appendix B says “for Δσ=3,” which conflicts with the paper’s definition.
Location: line 1660.
Issue: earlier Δσ=3/2−ν. A massive σ does not generally have Δσ=3.
Fix: clarify what weight is meant here. If this is the conformal weight of the massless pair/source rather than σ, rename it. -
Second derivative with respect to x0 is written incorrectly.
x02∂x02−2x0∂x0.
Locations: Eq. (B.15), lines 1691, 1693, and line 1694 text; also Eq. (B.37), line 1833.
Current: x02∂x02.
Issue: this denotes derivative with respect to x02, not the second derivative with respect to x0.
Fix: use -
Eq. (B.32) has an incorrect SK summation index.
Kb(k3,k4,η1,η0)=g3c=±∑(ic)∫η0−∞⋯Dbcσ(s,η1,η2)Kcϕ(k3,η2)Kcϕ(k4,η2).
Location: line 1803.
Current:\sum_{b=\pm}(ic)with c not defined.
Fix: -
Eq. (B.33) double-counts the SK branch sum unless the seed is redefined.
Locations: lines 1810 and 1815.
Issue: line 1810 contains ∑b(ib)I^, while line 1815 defines I^ itself with ∑b(ib).
Fix: either remove the sum from line 1810 or define I^ without the branch sum. -
Eq. (B.36) evaluates a boundary derivative at the wrong argument.
∂1K^b(x0,x0,v).
Location: line 1825.
Current: ∂1K^b(x,x0,v) inside a boundary term.
Fix: -
Typo in the composite-propagator identity.
∂1(K^+(x0,x0,v)−K^+(x0,x0,v))=0.
Location: line 1840.
Current:Fix:
∂1(K^+(x0,x0,v)−K^−(x0,x0,v))=0. -
Coefficient dpq in Eq. (B.41) is dimensionally inconsistent.
Location: line 1859.
Current denominator: q2−3q+m2.
Issue: m2 is dimensionful unless H=1 has been imposed. Elsewhere the dimensionless combination is m2/H2.
Fix: replace by m2/H2, or define m in this equation as dimensionless. Also check the numerator m2. -
Set-exclusion notation is wrong in Eq. (B.41).
Location: line 1860.
Current: q={0,1}.
Fix: q∈/{0,1}. -
Undefined α± appears after defining α~±.
Location: line 1900.
Current: H2α+α−(β0+b)/(πm2cosπν).
Issue: Eq. (B.46) defines α~±, not α±.
Fix: use one notation consistently. -
Higher-derivative contact relation is missing a power of □.
ϕ2(∇lϕ)2≃2−lϕ2□(ϕ2).
Location: line 1927.
Current:Issue: for general l, this should presumably involve □l, consistent with the commented-out line 946.
ϕ2(∇lϕ)2≃2−lϕ2□l(ϕ2),
Fix:if this is the intended identity.
-
Appendix C has an f12/f22 typo.
Location: line 2012.
Current: “while f22 again has a complicated form…”
Issue: the surrounding equations are about f12.
Fix: replace f22 by f12. -
Eq. (C.13) likely has the wrong function on the right-hand side.
f22(u)=f21(u)−3f2(u).
Location: line 2024.
Current:Issue: from the preceding relation f21=f11−3f1, one would expect at the next order something like
f22=f12−3f2,not f21−3f2.
Fix: verify the expansion of the hypergeometric solutions and correct this relation. -
Wrong cross-reference in Appendix C.
Location: line 2044.
Current: “The \crefeq:mastereq3pt becomes…”
Issue: the equation discussed is the four-point exchange equation, not the 3-point master equation.
Fix: refer to the relevant four-point bootstrap equation, probably Eq. (B.37) or Eq. (B.39). -
Eq. (3.20) correction term may have an inconsistent mixing operator.
Location: line 740.
Current: correction integral uses Ib,g3ϕ2σ×λ2ϕσ, while the surrounding bispectrum uses λ2ϕσ˙.
Fix: either restore the dot, or add a sentence explaining why the correction term is written with the undifferentiated mixing. -
Eq. (3.16) defines a rescaled propagator using k3 although the statement is general.
K^ϕ(k,η)≡2k3Kϕ(k,η),
Location: line 698.
Current: K^ϕ≡2k33Kϕ.
Fix: writeor explicitly say this is for the k3 leg.
-
The conversion from k∂k to a ϕ˙ insertion misses normalization factors.
Location: line 702.
Issue: ϕ˙=a−1ϕ′=−Hηϕ′, so η∂η differs by −H−1˙ factors and possible signs.
Fix: say “up to the corresponding factor of −H” or write the exact relation. -
Boundary-pair notation in Sec. 4.2 looks like subtraction.
ϕ′ϕσ−ϕ2σ′,ϕ2σ−ϕ′ϕσ′
Locations: lines 1203, 1204, 1256, 1278.
Current:etc.
ϕ′ϕσ×ϕ2σ′.
Issue: the dash denotes a pairing of two boundary vertices, not a subtraction.
Fix: use ×, “paired with,” or comma notation: -
Eq. (4.14) uses a=± as a branch label, which conflicts visually with the scale factor a(η).
Location: line 1162.
Fix: use b=± or s=± for the branch label. -
Eq. (4.16) prefactor should be rechecked.
H4η1η231
Location: lines 1188–1194.
Issue: the factoris not obviously consistent with the stated boundary vertices a−2ϕ′ϕσ′ and ϕ2σ.
Fix: rederive the powers of a(η0) in this example and state the vertex normalizations explicitly. This one is a “check” item rather than a definite error.
B. Text, grammar, and presentation fixes
-
Abstract: singular/plural mismatch.
Location: line 167.
Current: “a more systematic investigations”
Fix: “a more systematic investigation” or “more systematic investigations.” -
Abstract: awkward boost-breaking sentence.
Location: lines 162–166.
Current: “For theories with broken dS boost, through boundary terms, we reduce…”
Fix:
“For theories with broken dS boosts, we use IBP/EoM relations to reduce exchange correlators from bulk interactions to a basis of independent templates, and then classify the boundary-boundary and boundary-bulk contributions…” -
Affiliation spacing.
Locations: lines 135 and 139.
Current:P.R.China
Fix:P.R. China. -
Intro: “integration-by-parts” as a noun.
Location: line 196.
Current: “an integration-by-parts”
Fix: “integration by parts” or “an integration-by-parts relation.” -
Intro: grammar around EoM terms.
Location: line 196.
Current: “the terms in the Lagrangian being proportional to the equation of motion”
Fix: “terms in the Lagrangian proportional to the equations of motion.” -
Intro: flat-space boundary condition phrasing.
Location: line 198.
Current: “the future and past infinity”
Fix: “future and past infinity” or “past and future infinity.” -
Intro: single-field phrasing.
Location: line 207.
Current: “For single field inflation scenario”
Fix: “For single-field inflation scenarios” or “In the single-field inflation scenario.” -
Intro: “towards” should be “of/into.”
Location: line 218.
Current: “systematic investigation towards the boundary contributions”
Fix: “systematic investigation of boundary contributions” or “into boundary contributions.” -
Intro: hyphenation.
Location: line 226.
Current: “field-redefinitions”
Fix: “field redefinitions.” -
Intro: awkward verb phrase.
Location: lines 226–227.
Current: “and then have them compared and matched”
Fix: “and then compare and match them order by order…” -
Outline: singular/plural mismatch.
Location: line 251.
Current: “this type of boundary terms … yields”
Fix: “this type of boundary term … yields” or “these boundary terms … yield.” -
Notation: capitalization.
Location: line 264.
Current: “de Sitter Universe”
Fix: “de Sitter universe.” -
Notation: avoid
$$...$$.
Location: line 275.
Fix: replace by\[…\]or a numberedequationenvironment. -
Notation: line break command at paragraph end.
Location: line 311.
Issue: paragraph ends with\\.
Fix: remove it. -
Sec. 2 opening sentence is awkward.
Location: line 337.
Current: “which is concluded as several diagrammatic relations.”
Fix: “which we summarize as several diagrammatic relations.” -
Sec. 2 wording.
Location: line 341.
Current: “shares certain similarity with”
Fix: “shares some similarities with.” -
Sec. 2: formal tone.
Location: line 413.
Current: “Now let’s begin…”
Fix: “We begin…” -
Sec. 2: repeated “Then.”
Location: lines 414–416.
Fix: vary the sentence structure. -
Sec. 2: possessive typo.
Location: line 462.
Current: “it’s spatial derivatives”
Fix: “its spatial derivatives.” -
Sec. 2.2: stray
~line.
Location: line 536.
Fix: delete the standalone~. -
Sec. 3: informal opening.
Location: line 547.
Current: “Let’s start…”
Fix: “We start…” -
Sec. 3.1.1: quasi-single-field wording.
Location: line 567.
Current: “in quasi-single field scenario”
Fix: “in the quasi-single-field scenario.” -
Fig. 2 caption: punctuation.
Location: line 571.
Current: “interaction ϕ2σ .”
Fix: remove the space before the period. -
Sec. 3.1.2: phrase with unnecessary comma.
Location: line 630.
Current: “It is important to notice that, the…”
Fix: “It is important to note that the…” -
Sec. 3.1.3: adjective order.
Location: line 653.
Current: “late-time derivative finite exchange”
Fix: “late-time finite derivative exchange.” -
Fig. 4 block: missing space after environment.
Location: line 676.
Current:\end{small}The
Fix: add a blank line or space after\end{small}. -
Sec. 3.1.4: sentence fragment.
Location: line 690.
Current: “And the relation is”
Fix: “The relation is…” -
Sec. 3.1.4: spacing before cross-reference.
Location: line 704.
Current:in ~\cref
Fix:in~\cref. -
Sec. 4.1: “generalization” spelling consistency.
Location: line 1001.
Current: “generalization” while paper mostly uses British “generalised” elsewhere.
Fix: pick US or UK spelling consistently. -
Appendix A: duplicated word.
Location: line 1517.
Current: “let’s first look at the the 1st variation”
Fix: “we first look at the first variation.” -
Appendix A: informal “let’s.”
Locations: lines 1517 and elsewhere.
Fix: replace by “we.” -
Appendix A: typo in source labels.
Locations: lines 1511, 1551, 1557, etc.
Current:J_1^+,J_1^-appear in places where probably J+, J− are intended.
Fix: remove the spurious subscript1unless there is a source J1 defined. -
Appendix A: grammar around ghost fields.
Location: line 1454.
Current: “where c is ghost field.”
Fix: “where c is a ghost field.” -
Appendix A footnote 8: subject-verb agreement.
Location: line 1459.
Current: “the Jacobian only contribute”
Fix: “the Jacobian only contributes.” -
Appendix B: grammar.
Location: line 1707.
Current: “which could be understood as straight consequence”
Fix: “which can be understood as a direct consequence.” -
Appendix B: grammar.
Location: line 1710.
Current: “each Δ appears in the bootstrap equation indicates…”
Fix: “each Δ appearing in the bootstrap equation indicates…” -
Appendix B footnote 11: grammar.
Location: line 1717.
Current: “can no longer justify if”
Fix: “can no longer determine whether.” -
Appendix B: capitalization after subsection opening.
Location: line 1794.
Current: “In this subsection, We want…”
Fix: “In this subsection, we…” -
Appendix B: informal phrase.
Location: line 1794.
Current: “We want to compare…”
Fix: “We compare…” -
Appendix B: “It’s easy” tone.
Location: line 1926.
Fix: “It is straightforward…” -
Appendix B: subject-verb agreement.
Location: line 1927.
Current: “the contact diagram … are order by order correspond”
Fix: “the contact diagram … corresponds order by order…” -
Appendix C: grammar.
Location: line 1971.
Current: “with especially interest”
Fix: “with particular interest.” -
Appendix C: subject-verb agreement.
Location: line 1983.
Current: “others gives”
Fix: “the others give.” -
Appendix C: typo.
Location: line 2053.
Current: “remained part”
Fix: “remaining part.” -
Appendix C: article.
Location: line 2057.
Current: “we find a inhomogeneous solution”
Fix: “we find an inhomogeneous solution.” -
Appendix C: subject-verb agreement.
Location: line 2068.
Current: “the O(ϵ−1) terms becomes”
Fix: “the O(ϵ−1) terms become.”
C. Labels, references, and LaTeX hygiene
-
Several
\label{...}entries contain spaces.
Examples:
\label{field redef},\label{general EFT},\label{table 1},\label{table 2},\label{SD eqn},\label{bootstrap equality},\label{modified bootstrap equation},\label{contact bootstrap},\label{table 6},\label{light contact},\label{contact light},\label{momentum loop integral}.
Issue: LaTeX tolerates some of these, but they are fragile and bad style.
Fix: use labels such assec:field-redef,sec:general-eft,tab:trispectrum-count,eq:sd, etc. -
Duplicate bibliography entries.
Locations: references [49]/[74] and [53]/[75].
Issue: [49] and [74] appear to be the same Pimentel–Wang paper; [53] and [75] appear to be the same Wang–Pimentel–Achúcarro paper.
Fix: merge duplicate entries and update citations. -
Reference [48] and several later references appear to be future-dated relative to the current draft’s implied literature timeline.
Location: references [48], [57]–[68], [78]–[80].
Issue: these may be intended if the paper is being drafted later, but some arXiv IDs such as2512...and2605...should be double-checked before submission.
Fix: verify each future-dated arXiv reference and ensure the bibliography is not carrying placeholder/generated entries. -
Figure filename typo.
Location: line 811.
Current:fig/corresponce.pdf
Fix: rename tofig/correspondence.pdfand update the TeX. -
Figure filename with space.
Location: line 1457.
Current:fig/ghost diagram.png
Fix: rename tofig/ghost_diagram.pngfor portability. -
The uploaded source does not compile in a clean environment without
jcapmod.sty.
Location: preamble line 1.
Issue:\documentclass[a4paper]{jcapmod}requires the style/class file to be present.
Fix: includejcapmod.cls/jcapmod.stywith the source bundle, or switch to the standard JCAP class if appropriate. -
\captionpackage is loaded twice.
Locations: lines 20 and 22.
Fix: keep only one\usepackage{caption}. -
Manual page dimensions and
geometryare both used.
Locations: lines 57–61 and line 23.
Issue: this can lead to unexpected layout conflicts.
Fix: usegeometryoptions only, or removegeometryif the class handles the layout. -
Color name
cyanis redefined.
Location: line 104.
Current:\definecolor{cyan}{RGB}{...}
Issue:cyanis a standard color name; redefining it may cause confusion.
Fix: use a custom name, e.g.\definecolor{mycyan}{RGB}{...}. -
Many unused packages/macros appear in the preamble.
Examples:tikz-feynman,youngtab,tensor,appendix, custom title machinery, several author-comment macros.
Fix: remove packages/macros not needed for the final manuscript to reduce warnings and dependency problems. -
Hyphenation consistency: “late time” versus “late-time.”
Locations: throughout; e.g. “late time divergence” appears in Appendix B/C, while the main text often uses “late-time divergence.”
Fix: use “late-time” adjectivally: “late-time divergence,” “late-time boundary,” “late-time limit.” -
Hyphenation consistency: “non derivative/non-derivative,” “boost breaking/boost-breaking,” “single field/single-field.”
Fix: standardize to “non-derivative,” “boost-breaking,” “single-field” when used adjectivally. -
Notation consistency: ϕ versus φ.
Issue: the manuscript mostly uses\varphi, but some figure labels/captions and comments use\phi.
Fix: use one notation consistently in the final figures and captions. -
Notation consistency: dS, dS, and de Sitter.
Issue: the text alternates among “dS boost,” “dS-invariant,” “de Sitter Universe,” etc.
Fix: use “de Sitter” in prose and “dS” in technical compounds after defining it once. -
“EoM” singular/plural.
Issue: the paper uses “EoM terms,” “equation of motion,” and “equations of motion” somewhat interchangeably.
Fix: for multiple fields/operators, use “equations of motion” or “EoM terms”; for one field, use “the equation of motion.” -
Use of ∝ in Eqs. (3.9) and (3.10) despite giving explicit equalities.
Locations: lines 642 and 645.
Issue: the equations write\proptobefore explicit right-hand sides with coefficients.
Fix: either use equality and define the exact normalization, or keep ∝ and remove exact numerical coefficients. -
Ambiguous use of “boundary contributions caused by IBP and EoM.”
Location: conclusion lines 1378–1380.
Issue: EoM terms do not “cause boundary correlators” in the same way as IBP boundary terms; they collapse exchange diagrams into contact terms.
Fix: say “we identify late-time divergent contributions generated by the IBP/EoM decomposition, including boundary terms and contact terms from EoM insertions.” -
“In the end” is too informal for the final paragraph.
Location: line 1404.
Fix: “Finally,” or “Another interesting direction is…” -
Comma splice in BEFT paragraph.
Location: line 1397.
Current: “… reheating surface, For instance…”
Fix: replace comma with period and lowercase “for”: “… reheating surface. For instance…” -
“This type of divergences” grammar.
Location: line 1406.
Fix: “This type of divergence” or “These divergences.” -
“Boundary conformal anomalies” should be defined before being used as an interpretive phrase.
Locations: Sec. 3 opening and Appendix B.
Issue: the term is used as if already standard in the paper.
Fix: add one explanatory sentence near the start of Sec. 3 or Appendix B: e.g. “By boundary conformal anomaly we mean the anomalous source term in the momentum-space conformal Ward identity induced by the late-time cutoff.” -
Some displayed equations use inconsistent cutoff limits η0 versus η0−.
Examples: Eqs. (2.4), (2.8), (2.9), (2.10), Appendix A.
Fix: choose one convention and state it once. Use η0− only where avoiding boundary delta-functions is essential. -
Several instances of “strictly vanish” / “vanishes strictly” should specify whether this is due to the SK branch sum, the late-time limit, or exact mode-function identities.
Locations: Secs. 3.1.2 and 4.2.
Fix: add a parenthetical reason in the first occurrence of each mechanism. -
The paper uses both □ and ∂2 in places where only □ is correct on dS.
Locations: Fig. 1 caption and a few schematic passages.
Fix: use □ for covariant d’Alembertian; reserve ∂2 for flat or spatial derivatives with explicit definition.
D. Suggested triage order
I would fix in this order: first the active comments/placeholders; then the normalization and SK-sign issues in Eqs. (1.7), (1.8), (3.21); then the Sec. 3.3 curvature/recursion issue; then the boost-breaking operator/EOM issues in Sec. 4; then the Appendix A field-redefinition/Jacobian claims; finally the bibliography, labels, and copyediting.
You said:
ChatGPT said:
Yes. The branch sign is standard in the +/− Schwinger–Keldysh basis. With the conventions used in your draft, the correct identity is
(□η−m2)Dbc(k,η,η′)=iba−4(η)δ(η−η′)δbc=ib(−Hη)4δ(η−η′)δbc,where b=+1 on the + branch and b=−1 on the − branch. Equivalently, one can write it without an explicit b only if one defines a contour delta function
δCbc(η−η′)≡bδbcδ(η−η′).So Eq. (1.8) is okay only if δbc is secretly meant as the contour delta. If it is the ordinary Kronecker delta, the b is missing.
Your own draft already uses the branch-signed version later: in Sec. 3.1.2/Eq. (3.6), the internal σ propagator is written as satisfying an ib(Hη)4δ-type equation, and Appendix B uses the dimensionless version
(x2∂x2−2x∂x+x2+m2/H2)D^bcσ=ibx4δbcδ(x−y).Appendix A also summarizes the Green-function identities as (□−m2)Δbc=ibδ(4)δbc.
The quickest derivation is from the quadratic SK action. For a scalar,
S0[ϕ]=21∫d4x−gϕ(□−m2)ϕup to boundary terms. In SK,
SSK(2)=S0[ϕ+]−S0[ϕ−]=21b=±∑b∫d4x−gϕb(□−m2)ϕb.Thus the inverse propagator on branch b is b(□−m2). Since the Gaussian propagator is the inverse of the quadratic kernel with the usual i,
b(□−m2)Dbc(x,x′)=i−gδbcδ(4)(x−x′),and multiplying by b gives
(□−m2)Dbc(x,x′)=ib−gδbcδ(4)(x−x′).After stripping the spatial momentum delta function and using −g=a4=(−Hη)−4, this becomes the formula above.
There is also a useful mode-function check. With your definitions,
D++(η,η′)=u(η)u∗(η′)θ(η−η′)+u∗(η)u(η′)θ(η′−η),so acting with □η−m2 gives only the derivative of the step function at η=η′. Using the canonical Wronskian, one obtains
(□η−m2)D++=+ia−4δ(η−η′),whereas the anti-time-ordered propagator D−− has the opposite step-function ordering, hence
(□η−m2)D−−=−ia−4δ(η−η′).The Wightman functions D+− and D−+ contain no step-function singularity in this variable and are homogeneous. This is exactly summarized by ibδbc.
For references, the most directly relevant one for your notation is Chen, Wang, and Xianyu, Schwinger-Keldysh Diagrammatics for Primordial Perturbations. It gives a self-contained SK diagrammatic setup for primordial perturbations, defines the four +/− propagators, and emphasizes that the −-type vertex comes with the extra minus sign; it also notes that derivatives acting on time-ordered/anti-time-ordered propagators must include derivatives of the step functions, which is precisely where the delta-function source above comes from. arXiv ar5iv
A good footnote/correction in your draft would be:
TeXHere \(b=\pm1\) denotes the branch of the first time argument. Equivalently,
one may write the right-hand side using the contour delta function
\(\delta_{\cal C}^{bc}=b\,\delta^{bc}\delta(\eta-\eta')\).
and change Eq. (1.8) to
TeX(\Box_\eta-m^2)D^{bc}(k,\eta,\eta')
= i\,b\,(-H\eta)^4\delta(\eta-\eta')\delta^{bc}.