Displacement Field Analysis via Optimal Transport: Multi-Tracer Approach to Cosmological Reconstruction
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arXiv
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| Autores principales: | , , , , |
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| Formato: | Preprint |
| Publicado: |
2024
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| _version_ | 1866929281440940032 |
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| author | Nikakhtar, Farnik Sheth, Ravi K. Padmanabhan, Nikhil Lévy, Bruno Mohayaee, Roya |
| author_facet | Nikakhtar, Farnik Sheth, Ravi K. Padmanabhan, Nikhil Lévy, Bruno Mohayaee, Roya |
| contents | We demonstrate the effectiveness of one of the many multi-tracer analyses enabled by Optimal Transport (OT) reconstruction. Leveraging a semi-discrete OT algorithm, we determine the displacements between initial and observed positions of biased tracers and the remaining matter field. With only redshift-space distorted final positions of biased tracers and a simple premise for the remaining mass distribution as input, OT solves the displacement field. This extracted field, assuming asymptotically uniform density and a gradient flow displacement, enables reconstruction of the initial overdensity fluctuation field. We show that the divergence of the OT displacement field is a good proxy of the linear density field, even though the method never assumes the linear theory growth. Additionally, this divergence field can be combined with the reconstructed protohalos to provide a higher signal-to-noise measurement of the BAO standard ruler than was possible with either measurement individually. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2403_11951 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Displacement Field Analysis via Optimal Transport: Multi-Tracer Approach to Cosmological Reconstruction Nikakhtar, Farnik Sheth, Ravi K. Padmanabhan, Nikhil Lévy, Bruno Mohayaee, Roya Cosmology and Nongalactic Astrophysics We demonstrate the effectiveness of one of the many multi-tracer analyses enabled by Optimal Transport (OT) reconstruction. Leveraging a semi-discrete OT algorithm, we determine the displacements between initial and observed positions of biased tracers and the remaining matter field. With only redshift-space distorted final positions of biased tracers and a simple premise for the remaining mass distribution as input, OT solves the displacement field. This extracted field, assuming asymptotically uniform density and a gradient flow displacement, enables reconstruction of the initial overdensity fluctuation field. We show that the divergence of the OT displacement field is a good proxy of the linear density field, even though the method never assumes the linear theory growth. Additionally, this divergence field can be combined with the reconstructed protohalos to provide a higher signal-to-noise measurement of the BAO standard ruler than was possible with either measurement individually. |
| title | Displacement Field Analysis via Optimal Transport: Multi-Tracer Approach to Cosmological Reconstruction |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2403.11951 |