Abstract
We analyze the signatures of inflationary models that are coupled to interacting field theories, a basic class of multifield models also motivated by their role in providing dynamically small scales. Near the squeezed limit of the bispectrum, we find a simple scaling behavior determined by operator dimensions, which are constrained by the appropriate unitarity bounds. Specifically, we analyze two simple and calculable classes of examples: conformal field theories (CFTs), and large-N CFTs deformed by relevant time-dependent double-trace operators. Together these two classes of examples exhibit a wide range of scalings and shapes of the bispectrum, including nearly equilateral, orthogonal and local non-Gaussianity in different regimes. Along the way, we compare and contrast the shape and amplitude with previous results on weakly coupled fields coupled to inflation. This signature provides a precision test for strongly coupled sectors coupled to inflation via irrelevant operators suppressed by a high mass scale up to ~ 103 times the inflationary Hubble scale.
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References
L. Senatore and M. Zaldarriaga, The Effective Field Theory of Multifield Inflation, JHEP 04 (2012) 024 [arXiv:1009.2093] [INSPIRE].
D. Lopez Nacir, R.A. Porto, L. Senatore and M. Zaldarriaga, Dissipative effects in the Effective Field Theory of Inflation, JHEP 01 (2012) 075 [arXiv:1109.4192] [INSPIRE].
J.M. Maldacena, Non-Gaussian features of primordial fluctuations in single field inflationary models, JHEP 05 (2003) 013 [astro-ph/0210603] [INSPIRE].
D. Salopek and J. Bond, Nonlinear evolution of long wavelength metric fluctuations in inflationary models, Phys. Rev. D 42 (1990) 3936 [INSPIRE].
A.D. Linde and V.F. Mukhanov, Nongaussian isocurvature perturbations from inflation, Phys. Rev. D 56 (1997) 535 [astro-ph/9610219] [INSPIRE].
G. Dvali, A. Gruzinov and M. Zaldarriaga, Cosmological perturbations from inhomogeneous reheating, freezeout and mass domination, Phys. Rev. D 69 (2004) 083505 [astro-ph/0305548] [INSPIRE].
L. Kofman, Probing string theory with modulated cosmological fluctuations, astro-ph/0303614 [INSPIRE].
M. Zaldarriaga, Non-Gaussianities in models with a varying inflaton decay rate, Phys. Rev. D 69 (2004) 043508 [astro-ph/0306006] [INSPIRE].
X. Chen and Y. Wang, Quasi-Single Field Inflation and Non-Gaussianities, JCAP 04 (2010) 027 [arXiv:0911.3380] [INSPIRE].
X. Chen and Y. Wang, Large non-Gaussianities with Intermediate Shapes from Quasi-Single Field Inflation, Phys. Rev. D 81 (2010) 063511 [arXiv:0909.0496] [INSPIRE].
E. Sefusatti, J.R. Fergusson, X. Chen and E. Shellard, Effects and Detectability of Quasi-Single Field Inflation in the Large-Scale Structure and Cosmic Microwave Background, JCAP 08 (2012) 033 [arXiv:1204.6318] [INSPIRE].
D. Baumann and D. Green, Signatures of Supersymmetry from the Early Universe, Phys. Rev. D 85 (2012) 103520 [arXiv:1109.0292] [INSPIRE].
X. Dong, B. Horn, E. Silverstein and G. Torroba, Unitarity bounds and RG flows in time dependent quantum field theory, Phys. Rev. D 86 (2012) 025013 [arXiv:1203.1680] [INSPIRE].
D. Baumann and L. McAllister, Advances in Inflation in String Theory, Ann. Rev. Nucl. Part. Sci. 59 (2009) 67 [arXiv:0901.0265] [INSPIRE].
L. McAllister and E. Silverstein, String Cosmology: A Review, Gen. Rel. Grav. 40 (2008) 565 [arXiv:0710.2951] [INSPIRE].
L. Randall and R. Sundrum, A large mass hierarchy from a small extra dimension, Phys. Rev. Lett. 83 (1999) 3370 [hep-ph/9905221] [INSPIRE].
S.B. Giddings, S. Kachru and J. Polchinski, Hierarchies from fluxes in string compactifications, Phys. Rev. D 66 (2002) 106006 [hep-th/0105097] [INSPIRE].
S. Kachru, R. Kallosh, A.D. Linde and S.P. Trivedi, De Sitter vacua in string theory, Phys. Rev. D 68 (2003) 046005 [hep-th/0301240] [INSPIRE].
S. Dimopoulos, S. Kachru, N. Kaloper, A.E. Lawrence and E. Silverstein, Generating small numbers by tunneling in multithroat compactifications, Int. J. Mod. Phys. A 19 (2004) 2657 [hep-th/0106128] [INSPIRE].
S. Dimopoulos, S. Kachru, N. Kaloper, A.E. Lawrence and E. Silverstein, Small numbers from tunneling between brane throats, Phys. Rev. D 64 (2001) 121702 [hep-th/0104239] [INSPIRE].
D. Baumann and D. Green, Desensitizing Inflation from the Planck Scale, JHEP 09 (2010) 057 [arXiv:1004.3801] [INSPIRE].
D. Baumann and D. Green, Inflating with Baryons, JHEP 04 (2011) 071 [arXiv:1009.3032] [INSPIRE].
A. Maleknejad and M. Sheikh-Jabbari, Gauge-flation: Inflation From Non-Abelian Gauge Fields, Phys. Lett. B 723 (2013) 224 [arXiv:1102.1513] [INSPIRE].
S. Dubovsky, A. Lawrence and M.M. Roberts, Axion monodromy in a model of holographic gluodynamics, JHEP 02 (2012) 053 [arXiv:1105.3740] [INSPIRE].
P. Adshead and M. Wyman, Chromo-Natural Inflation: Natural inflation on a steep potential with classical non-Abelian gauge fields, Phys. Rev. Lett. 108 (2012) 261302 [arXiv:1202.2366] [INSPIRE].
E. Silverstein and D. Tong, Scalar speed limits and cosmology: Acceleration from D-cceleration, Phys. Rev. D 70 (2004) 103505 [hep-th/0310221] [INSPIRE].
M. Alishahiha, E. Silverstein and D. Tong, DBI in the sky, Phys. Rev. D 70 (2004) 123505 [hep-th/0404084] [INSPIRE].
X. Chen, M.-x. Huang, S. Kachru and G. Shiu, Observational signatures and non-Gaussianities of general single field inflation, JCAP 01 (2007) 002 [hep-th/0605045] [INSPIRE].
C. Cheung, P. Creminelli, A.L. Fitzpatrick, J. Kaplan and L. Senatore, The Effective Field Theory of Inflation, JHEP 03 (2008) 014 [arXiv:0709.0293] [INSPIRE].
L. Senatore, K.M. Smith and M. Zaldarriaga, Non-Gaussianities in Single Field Inflation and their Optimal Limits from the WMAP 5-year Data, JCAP 01 (2010) 028 [arXiv:0905.3746] [INSPIRE].
A.J. Tolley and M. Wyman, The Gelaton Scenario: Equilateral non-Gaussianity from multi-field dynamics, Phys. Rev. D 81 (2010) 043502 [arXiv:0910.1853] [INSPIRE].
S. Cremonini, Z. Lalak and K. Turzynski, Strongly Coupled Perturbations in Two-Field Inflationary Models, JCAP 03 (2011) 016 [arXiv:1010.3021] [INSPIRE].
A. Achucarro, J.-O. Gong, S. Hardeman, G.A. Palma and S.P. Patil, Features of heavy physics in the CMB power spectrum, JCAP 01 (2011) 030 [arXiv:1010.3693] [INSPIRE].
D. Baumann and D. Green, Equilateral Non-Gaussianity and New Physics on the Horizon, JCAP 09 (2011) 014 [arXiv:1102.5343] [INSPIRE].
S. Weinberg, Quantum contributions to cosmological correlations, Phys. Rev. D 72 (2005) 043514 [hep-th/0506236] [INSPIRE].
S.R. Behbahani and D. Green, Collective Symmetry Breaking and Resonant Non-Gaussianity, JCAP 11 (2012) 056 [arXiv:1207.2779] [INSPIRE].
L. Senatore and M. Zaldarriaga, On Loops in Inflation, JHEP 12 (2010) 008 [arXiv:0912.2734] [INSPIRE].
G.L. Pimentel, L. Senatore and M. Zaldarriaga, On Loops in Inflation III: Time Independence of zeta in Single Clock Inflation, JHEP 07 (2012) 166 [arXiv:1203.6651] [INSPIRE].
N. Dalal, O. Dore, D. Huterer and A. Shirokov, The imprints of primordial non-Gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects, Phys. Rev. D 77 (2008) 123514 [arXiv:0710.4560] [INSPIRE].
T. Baldauf, U. Seljak, L. Senatore and M. Zaldarriaga, Galaxy Bias and non-Linear Structure Formation in General Relativity, JCAP 10 (2011) 031 [arXiv:1106.5507] [INSPIRE].
A. Slosar, C. Hirata, U. Seljak, S. Ho and N. Padmanabhan, Constraints on local primordial non-Gaussianity from large scale structure, JCAP 08 (2008) 031 [arXiv:0805.3580] [INSPIRE].
T. Baldauf, U. Seljak and L. Senatore, Primordial non-Gaussianity in the Bispectrum of the Halo Density Field, JCAP 04 (2011) 006 [arXiv:1011.1513] [INSPIRE].
J. Norena, L. Verde, G. Barenboim and C. Bosch, Prospects for constraining the shape of non-Gaussianity with the scale-dependent bias, JCAP 08 (2012) 019 [arXiv:1204.6324] [INSPIRE].
E. Sefusatti, J.R. Fergusson, X. Chen and E. Shellard, Effects and Detectability of Quasi-Single Field Inflation in the Large-Scale Structure and Cosmic Microwave Background, JCAP 08 (2012) 033 [arXiv:1204.6318] [INSPIRE].
U. Seljak, Extracting primordial non-Gaussianity without cosmic variance, Phys. Rev. Lett. 102 (2009) 021302 [arXiv:0807.1770] [INSPIRE].
D. Babich, P. Creminelli and M. Zaldarriaga, The Shape of non-Gaussianities, JCAP 08 (2004) 009 [astro-ph/0405356] [INSPIRE].
P. Creminelli, A. Nicolis, L. Senatore, M. Tegmark and M. Zaldarriaga, Limits on non-Gaussianities from wmap data, JCAP 05 (2006) 004 [astro-ph/0509029] [INSPIRE].
WMAP collaboration, C. Bennett et al., Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results, Astrophys. J. Suppl. 208 (2013) 20 [arXiv:1212.5225] [INSPIRE].
F. Caracciolo and V.S. Rychkov, Rigorous Limits on the Interaction Strength in Quantum Field Theory, Phys. Rev. D 81 (2010) 085037 [arXiv:0912.2726] [INSPIRE].
D. Poland, D. Simmons-Duffin and A. Vichi, Carving Out the Space of 4D CFTs, JHEP 05 (2012) 110 [arXiv:1109.5176] [INSPIRE].
T. Suyama and M. Yamaguchi, Non-Gaussianity in the modulated reheating scenario, Phys. Rev. D 77 (2008) 023505 [arXiv:0709.2545] [INSPIRE].
N.S. Sugiyama, E. Komatsu and T. Futamase, Non-Gaussianity Consistency Relation for Multi-field Inflation, Phys. Rev. Lett. 106 (2011) 251301 [arXiv:1101.3636] [INSPIRE].
A. Lewis, The real shape of non-Gaussianities, JCAP 10 (2011) 026 [arXiv:1107.5431] [INSPIRE].
K.M. Smith, M. LoVerde and M. Zaldarriaga, A universal bound on N-point correlations from inflation, Phys. Rev. Lett. 107 (2011) 191301 [arXiv:1108.1805] [INSPIRE].
V. Assassi, D. Baumann and D. Green, On Soft Limits of Inflationary Correlation Functions, JCAP 11 (2012) 047 [arXiv:1204.4207] [INSPIRE].
A. Kehagias and A. Riotto, Operator Product Expansion of Inflationary Correlators and Conformal Symmetry of de Sitter, Nucl. Phys. B 864 (2012) 492 [arXiv:1205.1523] [INSPIRE].
K.M. Smith and M. LoVerde, Local stochastic non-Gaussianity and N-body simulations, JCAP 11 (2011) 009 [arXiv:1010.0055] [INSPIRE].
D. Baumann, S. Ferraro, D. Green and K.M. Smith, Stochastic Bias from Non-Gaussian Initial Conditions, JCAP 05 (2013) 001 [arXiv:1209.2173] [INSPIRE].
B. Grinstein, K.A. Intriligator and I.Z. Rothstein, Comments on Unparticles, Phys. Lett. B 662 (2008) 367 [arXiv:0801.1140] [INSPIRE].
S. Endlich, A. Nicolis and J. Wang, Solid Inflation, arXiv:1210.0569 [INSPIRE].
L. Senatore and M. Zaldarriaga, A Naturally Large Four-Point Function in Single Field Inflation, JCAP 01 (2011) 003 [arXiv:1004.1201] [INSPIRE].
I. Antoniadis, P.O. Mazur and E. Mottola, Conformal Invariance, Dark Energy and CMB Non-Gaussianity, JCAP 09 (2012) 024 [arXiv:1103.4164] [INSPIRE].
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Green, D., Lewandowski, M., Senatore, L. et al. Anomalous dimensions and non-gaussianity. J. High Energ. Phys. 2013, 171 (2013). https://doi.org/10.1007/JHEP10(2013)171
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DOI: https://doi.org/10.1007/JHEP10(2013)171