Recent Publications

On the streaming model for redshift-space distortions

The streaming model describes the mapping between real and redshift space for 2-point clustering statistics. Its key element is the probability density function (PDF) of line-of-sight pairwise peculiar velocities. Following a kinetic-theory approach, we derive the fundamental equations of the streaming model for ordered and unordered pairs. In the first case, we recover the classic equation while we demonstrate that modifications are necessary for unordered pairs. We then discuss several statistical properties of the pairwise velocities for DM particles and haloes by using a suite of high-resolution $N$-body simulations. We test the often used Gaussian ansatz for the PDF of pairwise velocities and discuss its limitations. Finally, we introduce a mixture of Gaussians which is known in statistics as the generalized hyperbolic distribution and show that it provides an accurate fit to the PDF. Once inserted in the streaming equation, the fit yields an excellent description of redshift-space correlations at all scales that vastly outperforms the Gaussian and exponential approximations. Using a principal-component analysis, we reduce the complexity of our model for large redshift-space separations. Our results increase the robustness of studies of anisotropic galaxy clustering and are useful for extending them towards smaller scales in order to test theories of gravity and interacting dark-energy models.
Monthly Notices of the Royal Astronomical Society, Volume 479, Issue 2, p.2256-2276, 2018

Teaching Experience

October 2018 – Present
Bonn, Germany

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April 2018 – August 2018
Bonn, Germany

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Course: Seminar on Astronomy and Astrophysics
Instructors: Prof. Dr. Cristiano Porciani, Dr. Emilio Romano-Díaz
October 2017 – March 2018
Bonn, Germany

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April 2017 – August 2017
Bonn, Germany

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Course: Introduction to Python
Lecturer: Dr. Thomas Erben
October 2016 – March 2017
Bonn, Germany

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July 2016 – September 2016
Bonn, Germany

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Course: Photmetry of Star Clusters
In-charge: Prof. Dr. Thomas Reiprich
March 2016 – May 2016
Bonn, Germany

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Course: Photmetry of Star Clusters
In-charge: Prof. Dr. Thomas Reiprich
April 2015 – September 2015
Bonn, Germany

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Course: Observational Cosmology
Lecturers: Prof. Dr. Cristiano Porciani, Dr. Kaustuv Basu
October 2014 – March 2015
Bonn, Germany

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