Revisiting the Lyth bound constraints on inflation from ACT DR6 results

[1]
A. H. Guth, Phys. Rev. D 23, 347 (1981)
[2]
A. D. Linde, Phys. Lett. B 108, 389 (1982)
[3]
A. Albrecht and P. J. Steinhardt, Phys. Rev. Lett. 48, 1220 (1982)
[4]
A. A. Starobinsky, Phys. Lett. B 91, 99 (1980)
[5]
V. F. Mukhanov and G. V. Chibisov, JETP Lett. 33, 532 (1981)
[6]
D. Baumann, Inflation, in Physics of the Large and the Small, edited by C. Csaki and S. Dodelson (Singapore: World Scientific, 2011), p. 523–686
[7]
J. Martin, C. Ringeval, and V. Vennin, Phys. Dark Univ. 5-6, 75 (2014)
[8]
D. H. Lyth, Phys. Rev. Lett. 78, 1861 (1997)
[9]
G. Efstathiou and K. J. Mack, JCAP 05, 008 (2005)
[10]
M. Alishahiha, E. Silverstein, and D. Tong, Phys. Rev. D 70, 123505 (2004)
[11]
D. Baumann and L. McAllister, Phys. Rev. D 75, 123508 (2007)
[12]
S. Antusch and D. Nolde, JCAP 05, 035 (2014)
[13]
N. K. Stein and W. H. Kinney, JCAP 04, 006 (2017)
[14]
Y. Akrami et al. (Planck Collaboration), Astron. Astrophys. 641, A10 (2020)
[15]
R. Bravo, G. A. Palma and S. Riquelme, JCAP 02, 004 (2020)
[16]
P. A. R. Ade et al. (BICEP/Keck Collaboration), Phys. Rev. Lett. 127(15), 151301 (2021)
[17]
Y.-F. Cai, J. Jiang, M. Sasaki et al., Phys. Rev. Lett. 127(25), 251301 (2021)
[18]
D. Paoletti, F. Finelli, J. Valiviita et al., Phys. Rev. D 106(8), 083528 (2022)
[19]
E. Calabrese et al. (Atacama Cosmology Telescope Collaboration), JCAP 11, 063 (2025)
[20]
Y. S. Furuta, Y. Hamada, and K. Kohri, Phys. Rev. D 112(10), 103517 (2025)
[21]
S. Akama and C. Lin, arXiv: 2602.20734
[22]
W. Xue and B. Chen, Phys. Rev. D 79, 043518 (2009)
[23]
A. Ashoorioon, K. Dimopoulos, M. M. Sheikh-Jabbari et al., Phys. Lett. B 737, 98 (2014)
[24]
A. Ashoorioon, K. Dimopoulos, M. M. Sheikh-Jabbari et al., JCAP 02, 025 (2014)
[25]
X. Li, S. Wang, and Z. Chang, Eur. Phys. J. C 75(6), 260 (2015)
[26]
X. Zhang and Y. Ling, JCAP 08, 012 (2007)
[27]
J. Hartong, A. Ploegh, T. Van Riet et al., Class. Quant. Grav. 23, 4593 (2006)
[28]
B. M. Gu, F. W. Shu, and K. Yang, Phys. Dark Univ. 47, 101744 (2025)
[29]
B. M. Gu, Y. P. Zhang, F. W. Shu et al., arXiv: 2602.07972
[30]
H. Zhang and L. Xu, JCAP 10, 003 (2020)
[31]
T. C. Li, T. Zhu, W. Zhao et al., JCAP 07, 005 (2024)
[32]
Q. G. Huang, Phys. Rev. D 91(12), 123532 (2015)
[33]
N. Aghanim et al. (Planck Collaboration), Astron. Astrophys. 641, A6 (2020)
[34]
R. Easther, W. H. Kinney, and B. A. Powell, JCAP 08, 004 (2006)
[35]
J. Garcia-Bellido, D. Roest, M. Scalisi et al., JCAP 09, 006 (2014)
[36]
J. Garcia-Bellido, D. Roest, M. Scalisi et al., Phys. Rev. D 90(12), 123539 (2014)
[37]
T. Louis et al. (Atacama Cosmology Telescope Collaboration), JCAP 11, 062 (2025)
[38]
R. Kallosh, A. Linde, and D. Roest, Phys. Rev. Lett. 135(16), 161001 (2025)
[39]
C. Dioguardi, A. J. Iovino, and A. Racioppi, Phys. Lett. B 868, 139664 (2025)
[40]
E. G. M. Ferreira, E. McDonough, L. Balkenhol et al., Phys. Rev. D 113(4), 043524 (2026)
[41]
E. McDonough and E. G. M. Ferreira, arXiv: 2512.05108
[42]
Y. Zhu, Q. Gao, Y. Gong et al., Eur. Phys. J. C 85(10), 1227 (2025)
[43]
Q. Gao, Y. Qian, Y. Gong et al., JCAP 08, 083 (2025)
[44]
Z. Yi, X. Wang, Q. Gao et al., Phys. Lett. B 871, 140002 (2025)
[45]
M. He, M. Hong, and K. Mukaida, JCAP 09, 080 (2025)
[46]
F. J. Qu et al. (ACT Collaboration), Astrophys. J. 962(2), 112 (2024)
[47]
Y. H. Pang, X. Zhang, and Q. G. Huang, Phys. Rev. D 111(12), 123504 (2025)
[48]
Q. Gao, Y. Gong, Z. Yi et al., Phys. Dark Univ. 50, 102106 (2025)
[49]
L. Liu, Z. Yi, and Y. Gong, arXiv: 2505.02407
[50]
Z. Z. Peng, Z. C. Chen, and L. Liu, Phys. Rev. D 113(6), 063527 (2026)
[51]
J. X. Li and S. Wang, Eur. Phys. J. C 85(11), 1308 (2025)
[52]
Z. Y. Peng and Y. S. Piao, Phys. Rev. D 113(2), 023544 (2026)
[53]
Z. Y. Peng, J. Q. Jiang, H. Wang et al., Phys. Rev. D 112(12), 123519 (2025)
[54]
P. J. Wu, T. N. Li, G. H. Du et al., Chin. Phys. C 50(4), 045105 (2026)
[55]
C. Fu, D. Lu, and S. J. Wang, Phys. Rev. D 113(8), L081304 (2026)
[56]
L. Feng, T. N. Li, G. H. Du et al., Phys. Dark Univ. 52, 102296 (2026)
[57]
F. Y. Zhang, R. Zhai, and L. Y. Chen, Chin. Phys. C 50(6), 065107 (2026)
[58]
W. Yang, C.,H. Wu, and Y. P. Hu, Phys. Lett. B 878, 140532 (2026)
[59]
H. G. Choi, P. Petrov, and S. C. Park, JCAP 04, 025 (2026)
[60]
S. D. Odintsov and V. K. Oikonomou, Phys. Lett. B 870, 139907 (2025)
[61]
J. Kim, X. Wang, Y.-l. Zhang et al., JCAP 09, 011 (2025)
[62]
Yogesh, A. Mohammadi, Q. Wu et al., JCAP 10, 010 (2025)
[63]
A. Mohammadi, Yogesh, and A. Wang, Phys. Lett. B 872, 140054 (2026)
[64]
A. Addazi, Y. Aldabergenov, D. Berkimbayev et al., arXiv: 2512.21167
[65]
A. Addazi, Y. Aldabergenov, and S. V. Ketov, Phys. Lett. B 869, 139883 (2025)
[66]
K. G. Zhang, C. Fu, J. F. He et al., arXiv: 2604.0214
[67]
Q. Y. Wang, Phys. Rev. D 113(12), L121302 (2026)
[68]
M. A. Sabogal, A. J. Iovino, and S. Vagnozzi, arXiv: 2606.31362
[69]
Z. Qiu, Y. Pang, and Q. Huang, Sci. China Phys. Mech. Astron. 69(6), 260413 (2026)
[70]
V. K. Oikonomou, Annals Phys. 492, 170547 (2026)
[71]
S. D. Odintsov and V. K. Oikonomou, Nucl. Phys. B 1025, 117384 (2026)
[72]
C. Armendariz-Picon, T. Damour, and V. F. Mukhanov, Phys. Lett. B 458, 209 (1999)
[73]
J. Garriga and V. F. Mukhanov, Phys. Lett. B 458, 219 (1999)
[74]
C. Cheung, P. Creminelli, A. L. Fitzpatrick et al., JHEP 03, 014 (2008)
[75]
X. Chen, M.-x. Huang, S. Kachru et al., JCAP 01, 002 (2007)
[76]
X. Gao and D. A. Steer, JCAP 12, 019 (2011)
[77]
X. H. Meng and P. Wang, Class. Quant. Grav. 21, L101 (2004)
[78]
C. Fu, P. Wu, and H. Yu, Phys. Rev. D 101(2), 023529 (2020)
[79]
X. M. Kuang and E. Papantonopoulos, JHEP 08, 161 (2016)
[80]
C. Wetterich, Phys. Lett. B 726, 15 (2013)
[81]
C. Wetterich, Phys. Lett. B 736, 506 (2014)
[82]
M. W. Hossain, R. Myrzakulov, M. Sami et al., Phys. Rev. D 90(2), 023512 (2014)
[83]
M. W. Hossain, R. Myrzakulov, M. Sami et al., Phys. Rev. D 89(12), 123513 (2014)
[84]
M. W. Hossain, R. Myrzakulov, M. Sami et al., Phys. Lett. B 737, 191 (2014)
[85]
V. F. Mukhanov and A. Vikman, JCAP 02, 004 (2006)
[86]
S. Unnikrishnan, Phys. Rev. D 78, 063007 (2008)
[87]
S. Unnikrishnan, V. Sahni, and A. Toporensky, JCAP 1208, 018 (2012)
[88]
S. Li and A. R. Liddle, JCAP 10, 011 (2012)
[89]
P. Pareek and A. Nautiyal, Phys. Rev. D 104(8), 083526 (2021)
[90]
S. Lola, A. Lymperis, and E. N. Saridakis, Eur. Phys. J. C 81(8), 719 (2021)
[91]
T. Zhu, A. Wang, G. Cleaver et al., Phys. Rev. D 90(10), 103517 (2014)
[92]
M. Liu, T. Y. He, B. Chen et al., Phys. Dark Univ. 49, 102039 (2025)
[93]
C.-Q. Geng, M. W. Hossain, R. Myrzakulov et al., Phys. Rev. D 92(2), 023522 (2015)
[94]
D. Baumann and D. Green, JCAP 05, 017 (2012)
[95]
G. Cabass, M. M. Ivanov, O. H. E. Philcox et al., Phys. Rev. Lett. 129(2), 021301 (2022)