%0 Generic %1 citeulike:13165860 %A Audren, Benjamin %A Figueroa, Daniel G. %A Tram, Thomas %D 2014 %K imported %T A note of clarification: BICEP2 and Planck are not in tension %U http://arxiv.org/abs/1405.1390 %X The apparent discrepancy between the value of the tensor-to-scalar ratio reported by the BICEP2 collaboration, \$r = 0.20^+0.07\_-0.05\$ at 68\% CL, and the Planck upper limit, \$r < 0.11\$ at 95\% CL, has attracted a great deal of attention. In this short note, we show that this discrepancy is mainly due to an `apples to oranges' comparison. The result reported by BICEP2 was measured at a pivot scale \$k\_* = 0.05\$ Mpc\$^-1\$, assuming \$n\_t = 0\$, whereas the Planck limit was provided at \$k\_* = 0.002\$ Mpc\$^-1\$, assuming the slow-roll consistency relation \$n\_t = -r/8\$. One should obviously compare the BICEP2 and Planck results under the same circumstances. By imposing \$n\_t = 0\$, the Planck constraint at \$k\_* = 0.05\$ Mpc\$^-1\$ becomes \$r < 0.135\$ at \$95\%\$ CL, which can be compared directly with the BICEP2 result. Once a plausible dust contribution to the BICEP2 signal is taken into account (DDM2 model), \$r\$ is reduced to \$r = 0.16^+0.06\_-0.05\$ and the discrepancy becomes of order \$1.3\sigma\$ only.

@misc{citeulike:13165860, abstract = {The apparent discrepancy between the value of the tensor-to-scalar ratio reported by the BICEP2 collaboration, \$r = 0.20^{+0.07}\_{-0.05}\$ at 68\% CL, and the Planck upper limit, \$r \< 0.11\$ at 95\% CL, has attracted a great deal of attention. In this short note, we show that this discrepancy is mainly due to an `apples to oranges' comparison. The result reported by BICEP2 was measured at a pivot scale \$k\_* = 0.05\$ Mpc\$^{-1}\$, assuming \$n\_t = 0\$, whereas the Planck limit was provided at \$k\_* = 0.002\$ Mpc\$^{-1}\$, assuming the slow-roll consistency relation \$n\_t = -r/8\$. One should obviously compare the BICEP2 and Planck results under the same circumstances. By imposing \$n\_t = 0\$, the Planck constraint at \$k\_* = 0.05\$ Mpc\$^{-1}\$ becomes \$r \< 0.135\$ at \$95\%\$ CL, which can be compared directly with the BICEP2 result. Once a plausible dust contribution to the BICEP2 signal is taken into account (DDM2 model), \$r\$ is reduced to \$r = 0.16^{+0.06}\_{-0.05}\$ and the discrepancy becomes of order \$1.3\sigma\$ only.}, added-at = {2019-03-25T08:20:55.000+0100}, archiveprefix = {arXiv}, author = {Audren, Benjamin and Figueroa, Daniel G. and Tram, Thomas}, biburl = {https://www.bibsonomy.org/bibtex/2504d576ef076ca9355483cc71ece742f/ericblackman}, citeulike-article-id = {13165860}, citeulike-linkout-0 = {http://arxiv.org/abs/1405.1390}, citeulike-linkout-1 = {http://arxiv.org/pdf/1405.1390}, day = 6, eprint = {1405.1390}, interhash = {22332efaf21f6e6c13e3012daa557fae}, intrahash = {504d576ef076ca9355483cc71ece742f}, keywords = {imported}, month = may, posted-at = {2014-05-12 06:44:37}, priority = {2}, timestamp = {2019-03-25T08:20:55.000+0100}, title = {{A note of clarification: BICEP2 and Planck are not in tension}}, url = {http://arxiv.org/abs/1405.1390}, year = 2014 }