%0 Generic %1 sarkar2019modelling %A Sarkar, Debanjan %A Majumdar, Suman %A Bharadwaj, Somnath %D 2019 %K library %T Modelling the post-reionization neutral hydrogen ($HI$) 21-cm bispectrum %U http://arxiv.org/abs/1907.01819 %X Measurements of the post-reionization 21-cm bispectrum $B_\rm HI(k_1,k_2,k_3)$ using various upcoming intensity mapping experiments hold the potential for determining the cosmological parameters at a high level of precision. In this paper we have estimated the 21-cm bispectrum in the $z$ range $1 z 6$ using semi-numerical simulations of the neutral hydrogen ($HI$) distribution. We determine the $k$ and $z$ range where the 21-cm bispectrum can be adequately modelled using the predictions of second order perturbation theory, and we use this to predict the redshift evolution of the linear and quadratic $HI$ bias parameters $b_1$ and $b_2$ respectively. The $b_1$ values are found to decreases nearly linearly with decreasing $z$, and are in good agreement with earlier predictions obtained by modelling the 21-cm power spectrum $P_HI(k)$. The $b_2$ values fall sharply with decreasing $z$, becomes zero at $z 3$ and attains a nearly constant value $b_2 - 0.36$ at $z<2$. We provide polynomial fitting formulas for $b_1$ and $b_2$ as functions of $z$. The modelling presented here is expected to be useful in future efforts to determine cosmological parameters and constrain primordial non-Gaussianity using the 21-cm bispectrum.

@misc{sarkar2019modelling, abstract = {Measurements of the post-reionization 21-cm bispectrum $B_{{\rm HI}}(\mathbf{k_1},\mathbf{k_2},\mathbf{k_3})$ using various upcoming intensity mapping experiments hold the potential for determining the cosmological parameters at a high level of precision. In this paper we have estimated the 21-cm bispectrum in the $z$ range $1 \le z \le 6$ using semi-numerical simulations of the neutral hydrogen (${\rm HI}$) distribution. We determine the $k$ and $z$ range where the 21-cm bispectrum can be adequately modelled using the predictions of second order perturbation theory, and we use this to predict the redshift evolution of the linear and quadratic ${\rm HI}$ bias parameters $b_1$ and $b_2$ respectively. The $b_1$ values are found to decreases nearly linearly with decreasing $z$, and are in good agreement with earlier predictions obtained by modelling the 21-cm power spectrum $P_{{\rm HI}}(k)$. The $b_2$ values fall sharply with decreasing $z$, becomes zero at $z \sim 3$ and attains a nearly constant value $b_2 \approx - 0.36$ at $z<2$. We provide polynomial fitting formulas for $b_1$ and $b_2$ as functions of $z$. The modelling presented here is expected to be useful in future efforts to determine cosmological parameters and constrain primordial non-Gaussianity using the 21-cm bispectrum.}, added-at = {2019-07-04T05:37:57.000+0200}, author = {Sarkar, Debanjan and Majumdar, Suman and Bharadwaj, Somnath}, biburl = {https://www.bibsonomy.org/bibtex/2fd87ff79c6762974228907cd14ce5785/gpkulkarni}, description = {Modelling the post-reionization neutral hydrogen (${\rm HI}$) 21-cm bispectrum}, interhash = {87b7000f4dcef6f520c29be7f59f39ba}, intrahash = {fd87ff79c6762974228907cd14ce5785}, keywords = {library}, note = {cite arxiv:1907.01819Comment: 10 pages, 8 figures, 1 table, MNRAS, submitted}, timestamp = {2019-07-04T05:37:57.000+0200}, title = {Modelling the post-reionization neutral hydrogen (${\rm HI}$) 21-cm bispectrum}, url = {http://arxiv.org/abs/1907.01819}, year = 2019 }