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Cited by 98Cosmology and Gravitation TheoriesNoncommutative and Quantum Gravity TheoriesBlack Holes and Theoretical Physics

Spectral running and non-Gaussianity from slow-roll inflation in generalized two-field models

Open access
Choi, Ki-Young, Hall, Lisa M H, Bruck, Carsten van de·2007·Journal of Cosmology and Astroparticle Physics
DOI 10.1088/1475-7516/2007/02/029
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Abstract

Theories beyond the standard model such as string theory motivate low energy effective field theories with several scalar fields which are not only coupled through a potential but also through their kinetic terms. For such theories we derive the general formulae for the running of the spectral indices for the adiabatic, isocurvature and correlation spectra in the case of two-field inflation. We also compute the expected non-Gaussianity in such models for specific forms of the potentials. We find that the coupling has little impact on the level of non-Gaussianity during inflation.

AI snapshot

Written from the paper’s full text.

TL;DR

The paper derives general slow-roll formulas for the running of adiabatic, isocurvature, and correlation spectral indices in generalized two-field inflation with kinetic coupling, and computes non-Gaussianity for product and sum potentials. It finds that the kinetic coupling has little impact on the level of non-Gaussianity during inflation, with \(f_{\rm NL}\sim 1/N\) and unobservable in the slow-roll examples considered.

Key findings

  • General expressions are obtained for the running spectral indices \(\alpha_\zeta\), \(\alpha_S\), and \(\alpha_C\); \(\alpha_S\) is independent of the correlation angle \(\Delta\), meaning it is fixed at horizon crossing and does not change thereafter.
  • The first non-Gaussianity term is approximated as \(-6/5 f_{\rm NL}^{(3)} \sim r/16\), too small to be observable; for Jordan-Brans-Dicke product potentials the second term gives \(-6/5 f_{\rm NL}^{(4)} \approx 1/(2N)\), with small coupling corrections such as \(\beta \phi/NM_P\) or \(\beta \phi^2/NM_P^2\).
  • For sum quadratic potentials, numerical results give \(f_{\rm NL}\sim 1/N\), and the authors conclude that \(\beta\) has little impact on the level of non-linearity.
  • Enough inflation in the JBD examples requires \(\beta<0.05\) for \(\phi_*,\chi_*<50M_P\) in model 1, and \(\beta<0.0005\) in model 2; analytical slow-roll approximations agree with numerical results within 5%.

Methods

  • The authors study a two-field action with a non-canonical kinetic term \(e^{2b(\phi)}\partial_\mu\chi\partial^\mu\chi\), derive background and perturbation equations in slow roll, and use the transfer-matrix formalism for adiabatic/isocurvature perturbations.
  • Non-Gaussianity is computed using the \(\delta N\) formalism for separable product potentials \(W=U(\phi)V(\chi)\) and sum potentials \(W=U(\phi)+V(\chi)\).
  • Specific models include Jordan-Brans-Dicke and Brans-Dicke-type product potentials with quartic or quadratic \(\chi\) potentials, plus sum quadratic potentials; numerical solutions of the background and Friedmann equations are obtained without assuming slow roll on a \(\phi\)-\(\chi\) grid.

Limitations

  • Stated: \(\alpha_C\) diverges at \(\Delta\to\pi/2\), but this divergence is not observable; no analytical approximation was found for models 3 and 4, so numerical results are given for simple sum-potential models.
  • Evident: the analysis is restricted to two scalar fields, slow-roll inflation, and specific separable potentials; the numerical grid uses initial values \(\phi_i\) and \(\chi_i\) with \(\dot\phi_i=\dot\chi_i=0\), and no full observational likelihood or parameter-estimation analysis is performed.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1088/1475-7516/2007/02/029

Cites

87 of 87 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

9 of 11 cited sources checked · 1 supported · 0 flagged · accuracy not yet measured

  • Premisecitation

    In the presence of multiple fields during inflation, the curvature perturbation ζ does not remain constant and varies because non-vanishing isocurvature perturbations act as a source term for the change of ζ.

    “However, in the presence of multiple fields during the inflationary epoch, ζ does not remain constant and varies since the non-vanishing isocurvature perturbations act as a source term for the change of ζ [5,6].”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites [5] source

      The perturbed-field-equations section (p. 7) says entropy perturbations can cause ζ to evolve on super-Hubble scales in a two-field model. But it also says ζ remains constant for adiabatic modes, and the Conclusions (p. 15) identify two-field regimes where it remains constant. The claim overstates this possibility as an inevitable consequence of multiple fields. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [6] source
  • Findingcitation

    The paper derives general formulae for the running of the spectral indices for the adiabatic, isocurvature and correlation spectra in the case of two-field inflation.

    “For such theories we derive the general formulae for the running of the spectral indices for the adiabatic, isocurvature and correlation spectra in the case of two-field inflation.”
    • Also stated in: § JCAP02(2007)029 · plain
      “We obtain the general formulae for the running of the spectral indices (adiabatic, non-adiabatic and correlated), following [27] and [28].”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [27] Barnaby N Cline J M, 2006

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [28] source

      Section IV (p. 5) gives spectral indices for adiabatic and isocurvature perturbations in an exact two-field inflationary solution. It does not provide general formulae for the running of those indices or for a correlation spectrum. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.
  • Interpretationcitation

    The first term -6/5 f(3)_NL is too small to be observable in CMB experiments.

    “which is certainly too small to be observable in CMB experiments.Also see [39].”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [39] Seery D, 2005, J. Cosmol. Astropart. Phys. source

      Section 2.3 (p. 10) identifies the first term as the momentum-dependent contribution, and the Conclusions (p. 21) say non-Gaussianity arising from microphysics is typically small when fluctuations are close to scale-invariance. The paper does not establish that this term is too small to be observable in CMB experiments; it also says the term can be important when the superhorizon contribution is absent. (LLM, conf=0.82)

      Experimental — accuracy not yet measured
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.
  • Findingnone given

    The coupling has little impact on the level of non-Gaussianity during inflation.

    “We find that the coupling has little impact on the level of non-Gaussianity during inflation.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.
  • Findingreasoning

    When b_phi = 0, the running spectral indices are given by θ, Δ and 9 slow-roll parameters.

    “However, considering the component fields (σ, s), H, T SS and ξ 2 sss do not appear in the running of spectral indices, which reduces the parameters to 11. Therefore the running spectral indices are given by: θ, Δ and 9 slow-roll parameters.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.
  • Classified as probably not a substantial claim. 13
  • May combine two claims. 23
  • The quote only partly states this claim. 1

  • Classified as probably not a substantial claim.

    Premisecitation

    The spectral indices are given in terms of slow-roll parameters as calculated in [28].

    “The spectral indices are best written in terms of slow-roll parameters.They have been calculated in [28] and are given by”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [28] source

      Section IV (pp. 5–6) calculates spectral indices for an exact inflationary solution and presents them as functions of p and tan θ. The passages do not give the indices in terms of slow-roll parameters, so that part of the attribution is unsupported by our copy. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Current observations limit the non-linearity parameter to |f_NL| < 100.

    “Current observations limit the non-linearity parameter, |f NL | < 100 [30].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [30] source

      The paper discusses linear perturbations (Section II, p. 2) and observational implications of correlated perturbations (Introduction, p. 1), but the passages do not give a bound on the non-linearity parameter. Searches for f_NL, non-Gaussianity, and the value 100 found no passage stating |f_NL| < 100. (LLM, conf=0.76)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingreasoning

    When b(φ) = 0, the calculation of f(4)_NL simplifies and the result is identical to that found in [38].

    “When b(ϕ) = 0, this calculation of f (4) NL simplifies, since B S = C S = G = H = 0, α u = α v = 1, (4.29) and the result is identical to that found in [38].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [38] source

      The bispectrum discussion (p. 2) says the paper calculates f_NL, but our copy does not decode the resulting formula. Searches for b(φ) and the named terms did not find the b(φ)=0 simplification, so the claimed identity between the two results cannot be checked from our copy. (LLM, conf=0.70)

      Experimental — accuracy not yet measured
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Similar cases with canonical kinetic terms were previously studied in [38], where they were shown not to generate significant non-Gaussianity.

    “Similar cases with canonical kinetic terms were previously studied in [38], where it was shown that they do not generate significant non-Gaussianity.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [38] source

      The two-component inflation-model example (p. 3) finds non-Gaussianity too small to observe, supporting the claim for that case. But another two-component model (p. 4) can yield |f_NL| > 1 under specified conditions. The paper therefore does not support the unqualified statement that similar cases do not generate significant non-Gaussianity; the passages also do not identify the models by their kinetic terms. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.

  • Classified as probably not a substantial claim.

    Premisecitation

    In previous work [38], for theories with canonical kinetic terms and a sum potential, f_NL ≈ 1/N.

    “In previous work, [38], for theories with canonical kinetic terms and a sum potential, f NL ≈ 1/N .”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [38] source

      In “A two-component inflation model” (p. 3), the paper gives N ∝ |θc/θ| and f_NL ≃ |θ/θc|, implying f_NL ∝ 1/N for that particular model. It does not establish the claimed result generally for theories with canonical kinetic terms and a sum potential; its other two-component example (p. 4) instead discusses conditions yielding |f_NL| > 1. (LLM, conf=0.82)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingreasoning

    In the slow-roll limit and on large scales, the evolutions of curvature and isocurvature perturbations can be written in terms of slow-roll parameters as ζ = BHS and Ṡ = -γHS.

    “In the slow-roll limit and on large scales, we find the evolutions of curvature and isocurvature perturbation can be written in terms of slow-roll parameters, ζ BHS, Ṡ -γHS, (2.18)”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.

  • May combine two claims.

    Findingnone given

    In the small β limit, *_φ < *_χ and the last two terms in equation (5.14) are negligible compared to the first two terms.

    “It can be noted that in this small β limit, * ϕ < * χ and the last two terms in this equation are negligible compared to the first two terms.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingreasoning

    For models with a sum of two quadratic potentials, due to the complexity of the analytic formula for f_NL, it is difficult to find an approximate equation.

    “We also considered models with a sum of two quadratic potentials.Due to the complexity of the analytic formula for f NL , it is difficult to find an approximate equation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingreasoning

    In this limit of β, equation (5.10) can be approximated by equation (5.11).

    “In this limit of β, we can approximate equation (5.10) further:”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    In the JBD example with quadratic and quartic potentials, the slow-roll parameter for field φ is given by the constant coupling parameter β, and the slow-roll condition for φ implies β itself has to be small.

    “One of the specific examples we have considered is the Jordan-Brans-Dicke theory with quadratic and quartic potentials.In this case, the slow-roll parameter for the field ϕ is given by the (constant) coupling parameter β, defined in equation (5.9).The slow-roll condition for the field ϕ implies that β itself has to be small.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    For V(χ)=λχ^n in JBD theory, using e = e_φ + e_χ = 1, N can be analytically solved in the slow-roll limit, yielding equation (5.10).

    “It is possible to consider the case V (χ) = λχ n .In this JBD theory, and using the fact that at the end of inflation e = e ϕ + e χ = 1, we can analytically solve N in the slow-roll”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The paper provides numerical results for simple models and showed that f_NL is unobservable for the slow-roll limit.

    “We therefore provide numerical results for simple models and showed that f NL 1 and is unobservable for the slow-roll limit.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    The results for model 4 are very similar to those of model 3 and are therefore not shown.

    “The results for model 4 are very similar to those of model 3 and are therefore not shown.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    Models 2a and 2b have a reflection symmetry about φ (θ→-θ) and/or χ (θ→π-θ).

    “Models 2a and 2b have a reflection symmetry about ϕ (θ → -θ) and/or χ (θ → π-θ).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingreasoning

    When b(φ) = 0, α = 1 and b = 0, restoring the symmetry between φ and χ in equation (4.10).

    “When b(ϕ) = 0, then α = 1 and b = 0, which means that the symmetry between ϕ and χ in equation (4.10) is restored.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.

  • May combine two claims.

    Findingreasoning

    All first- and second-order slow-roll parameters are proportional to and 2 respectively, making the primordial spectral indices proportional to 2 in the lowest order.

    “Hence, all the first-and second-order slow-roll parameters are proportional to and 2 respectively which make the primordial spectral indices proportional to 2 in the lowest order.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.
    • The authors state this as an assumption: In the Jordan-Brans-Dicke theory considered, β is a positive constant.

  • Classified as probably not a substantial claim.

    Findingreasoning

    Using equation (5.11), f_NL can be written in terms of the required e-folding number in the small β limit, yielding equation (5.15).

    “Using equation (5.11), f NL can be written in terms of the required e-folding number in the small β limit (required for enough inflation)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    For this sum potential, it is no longer possible to directly relate the parameters to and θ; however, if the ratio of masses is r=m_χ^2/m_φ^2, the slow-roll parameters can be rewritten in terms of , β and re^{-2b} only, as in equations (6.6)-(6.7).

    “It is no longer possible to directly relate the parameters to and θ.However, if we represent the ratio of masses by r = m 2 χ m 2 ϕ , (6.5) then the slow-roll parameters can be rewritten in terms of , β and re -2b only:”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The result for model 1b is almost identical to that for model 1a.

    “The result for model 1b is almost identical and is not shown.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.
    • The authors state this as an assumption: In the Jordan-Brans-Dicke theory considered, β is a positive constant.

  • May combine two claims.

    Findingreasoning

    For model 1a, B (defined in equation (2.19)) is identically zero due to cancelling slow-roll parameters, so from equation (2.18) the curvature perturbation remains constant after horizon crossing (ζ=0) for this JBD model with quartic potential.

    “As an aside, it can be noted that, for the specific case of model 1a, B (defined in equation (2.19)) is identically zero, due to a cancelling of the slow-roll parameters.This means that from equation (2.18) the curvature perturbation remains constant after horizon crossing ( ζ = 0) for this JBD model with quartic potential.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    We see the symmetry in figure 2 around the point (θ=π/2, Δ=π/2); after inflation, Δ is no longer dependent on the fields φ and χ, so this symmetry is not necessarily valid any more.

    “For this reason, we see the symmetry in figure 2 around the point (θ = π/2, Δ = π/2).However after inflation, Δ is no longer dependent on the fields ϕ and χ, thus this symmetry is not necessarily valid any more.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given

    Model 2b is almost identical to model 2a, so its numerical results are not shown.

    “Model 2b is almost identical to model 2a and the numerical results are not shown.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    In this case, an analytical formula for f_NL during inflation is given by equation (5.14) and is of order 1/N, where N is the total number of e-foldings.

    “In this case, an analytical formula for f NL during inflation is given by equation (5.14) and is of order 1/N , where N is the total number of e-foldings.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    α_S is determined at horizon crossing and does not change thereafter.

    “We note that the running spectral index of isocurvature perturbation, α S , is independent of Δ, which means that the α S is determined at horizon crossing and does not change thereafter.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A perfect CMB experiment cannot hope to detect |f_NL| < 3.

    “A perfect CMB experiment cannot hope to detect |f NL | < 3 [31].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] Creminelli P Senatore L Zaldarriaga M Tegmark M, 2006

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    As Δ → π/2, T_ζS is non-zero but very small, and the correlation amplitude would be small and therefore unobservable.

    “As Δ → π/2, T ζS is non-zero, but very small.In this limit, the correlation amplitude would be also small and therefore unobservable.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Study design and conductown data

    The analytical slow-roll approximations given in equations (5.14) and (5.20) were seen to agree within 5% with the numerical results.

    “The analytical slow-roll approximations given in equations (5.14) and (5.20) were seen to agree within 5%.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    The background equations of motion and the Friedmann equation were solved numerically without assuming slow-roll, in order to verify the analytical results.

    “In order to verify our analytical results of the previous section, we numerically solved the background equations of motion, equation (2.1) and the Friedmann equation, equation (2.2), not assuming slow-roll.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    θ is calculated at horizon crossing and depends on β and the initial values of φ and χ, whereas Δ represents evolution after horizon crossing and depends on the late-time evolution of the Universe.

    “We note that θ is calculated at horizon crossing and depends on β and the initial values of ϕ and χ, whereas Δ represents the evolution after horizon crossing and depends on the late time evolution of the Universe.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: During inflation, the fields follow the slow-roll limit.
    • The authors state this as an assumption: In the Jordan-Brans-Dicke theory considered, β is a positive constant.

  • May combine two claims.

    Interpretationreasoning

    As in model 1, in order to achieve enough inflation, the parameters are required to be small and hence -6/5 f_NL^(4) ≈ 1/2N.

    “As in model 1, in order to achieve enough inflation, the parameters are required to be small and hence -6 5 f (4) NL ≈ 1/2N.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    For the correlated spectral running α_C, there is a divergence at Δ → π/2, but this divergence is not observable.

    “For the correlated spectral running, α C , there is an divergence at Δ → π/2.This divergence is not observable.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    At Δ = π/2 (T_ζS = 0), there is no evolution in P_ζ and the amplitude of the correlation spectrum is zero, so it is impossible to define a spectral index or running at this point.

    “From equation (2.23), it can be seen that, for Δ = π/2 (T ζS = 0), there is no evolution in P ζ and the amplitude of the correlation spectrum is zero.It is therefore impossible to define a spectral index or running at this point.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationnone given

    Neither of these enhancement terms is significant, and in the slow-roll limit f_NL is not much enhanced by the coupling.

    “Neither of these terms are significant and in the slow-roll limit, f NL is not much enhanced by the coupling.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Because the sign of tan Δ is determined by the sign of α in equation (2.20) and α is proportional to sin 2θ for the potential in equation (5.1), reflection of φ or χ changes the sign of tan Δ before the end of inflation.

    “However since the sign of tan Δ is determined by the sign of α in equation (2.20) and α is proportional to sin 2θ for the potential in equation (5.1),The reflection of ϕ or χ changes also the sign of tan Δ before the end of inflation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    In order to achieve enough inflation, the parameters are required to be small and hence -6/5 f_NL^(4) ≈ 1/2N, which is unobservable.

    “It is clear that, in order to achieve enough inflation, the parameters are required to be small and hence -6 5 f (4) NL ≈ 1/2N, which is unobservable.”
    Quote in the paperSubstantial claim
35 of 35

  • The authors state this as an assumption.

    During inflation, the fields follow the slow-roll limit.

    “During inflation, the fields are assumed to follow the slow-roll limit, φ = σ cos θ -W ϕ 3H , χ = σ sin θe -b -W χ 3H e -2b , (2.16) H 2 (ϕ, χ) 1 3M 2 P W (ϕ, χ).”

  • The authors state this as an assumption.

    In the Jordan-Brans-Dicke theory considered, β is a positive constant.

    “where we assume β is a positive constant.”

  • The authors state this as an assumption.

    β is positive.

    “Assuming β to be positive, the effect of the coupling is”
3 of 3

Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. 10.1103/physrevd.63.0630xx · DOI
  2. Starobinsky A A, 1985, Pis. Zh. Eksp. Teor. Fiz., 42, 124
  3. Starobinsky A A, 1985, JETP Lett., 42, 152

Cited by

Sorted by citations

Related

Authors
Choi, K.-Y., Hall, L. M. H., & Bruck, C. V. D.
Affiliations
University of Sheffield (GB)
ORCID
Venue
Journal of Cosmology and Astroparticle Physics
Publisher
IOP Publishing
Published
2007-02-23
Volume
2007
Issue
02
Pages
029-029
ISSN
  • 1475-7508 (ISSN-L)
  • 1475-7516
DOI
10.1088/1475-7516/2007/02/029
OpenAlex
W2036888309
Semantic Scholar
b9b2149a2245f92040133211a22883cae608cc24
Cited by
98
References
48
Citations by year
2026: 1 · 2025: 2 · 2023: 2 · 2022: 2 · 2021: 3 · 2020: 2 · 2019: 2 · 2018: 8 · 2017: 6 · 2016: 3 · 2015: 7 · 2014: 6 · 2013: 8 · 2012: 9
FWCI
5.20
Type
journal article
Language
en
Open access
Locations
  • Journal of Cosmology and Astroparticle Physics (publishedVersion)
  • arXiv (Cornell University) (submittedVersion)
Topics
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Cosmology and Gravitation Theories
  • Physical Sciences › Physics and Astronomy › Statistical and Nonlinear Physics › Noncommutative and Quantum Gravity Theories
  • Physical Sciences › Physics and Astronomy › Nuclear and High Energy Physics › Black Holes and Theoretical Physics
Keywords
two-field inflation, slow-roll inflation, running of the spectral index, non-Gaussianity, isocurvature perturbations, adiabatic perturbations, correlation spectra, scalar field coupling, kinetic coupling, string cosmology, effective field theory

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