137 citations · 375 across the 27 of their papers we have counts for
29 papers
Basis function expansions of the two-point correlation function and reconstruction of the cosmological distance scale
Fatima Abd Alrahman, Farnik Nikakhtar, Marcello Musso +2
The shape of the correlation function of galaxy pairs can be used as a cosmological distance indicator. Most estimators of this shape require that one bin the pair counts, and cons…
Optimal Transport Reconstruction of Biased Tracers in Primordial Non-Gaussian Fields
Farnik Nikakhtar, Ravi K. Sheth, Nikhil Padmanabhan +2
Optimal transport provides an efficient method to infer the displacement of objects by mapping their initial positions to their present-day locations over cosmic time; equivalently…
Reducing the Dimensions of AGN Lightcurve Manifolds
Shoubaneh Hemmati, Jessica Krick, Daniel Stern +10
The Active Galactic Nuclei (AGN) glossary is vast and complex. Depending on selection method, observing wavelength, and brightness, AGNs are assigned distinct labels, yet the relat…
The Linear Point Standard Ruler with DESI DR1 and DR2 Data
N. Uberoi, F. Nikakhtar, N. Padmanabhan +45
The linear point, a purely geometric feature in the monopole of the two-point correlation function, has been proposed as an alternative standard ruler. Compared to the peak in the…
Protohalos and their connection to halo assembly, shape and structure
Farnik Nikakhtar, Daisuke Nagai, Marcello Musso +1
Protohalos, primordial regions in the initial cosmic density field that evolve into dark matter halos, are crucial for understanding cosmic structure formation. Motivated by the po…
Second public data release of the FIRE-2 cosmological zoom-in simulations of galaxy formation
Andrew Wetzel, Jenna Samuel, Pratik J. Gandhi +34
We describe the second data release (DR2) of the FIRE-2 cosmological zoom-in simulations of galaxy formation, from the Feedback In Realistic Environments (FIRE) project, available…
Data Release 1 of the Dark Energy Spectroscopic Instrument
DESI Collaboration, M. Abdul Karim, A. G. Adame +306
In 2021 May the Dark Energy Spectroscopic Instrument (DESI) collaboration began a 5-year spectroscopic redshift survey to produce a detailed map of the evolving three-dimensional s…
Extensive analysis of reconstruction algorithms for DESI 2024 baryon acoustic oscillations
X. Chen, Z. Ding, E. Paillas +64
Reconstruction of the baryon acoustic oscillation (BAO) signal has been a standard procedure in BAO analyses over the past decade and has helped to improve the BAO parameter precis…
Leveraging protohalos and scale-dependent bias to calibrate the BAO scale in real space
Sasha Gaines, Farnik Nikakhtar, Nikhil Padmanabhan +1
The location of the baryon acoustic oscillation (BAO) feature in the two-point correlation function (2PCF) of matter produces a standard ruler that is useful for the measurement of…
DESI Early Data Release Milky Way Survey Value-Added Catalogue
Sergey E. Koposov, C. Allende-Prieto, A. P. Cooper +40
We present the stellar value-added catalogue based on the Dark Energy Spectroscopic Instrument (DESI) Early Data Release. The catalogue contains radial velocity and stellar paramet…
Eigen-decomposition of Covariance matrices: An application to the BAO Linear Point
Jaemyoung Jason Lee, Farnik Nikakhtar, Aseem Paranjape +1
The Baryon Acoustic Oscillation (BAO) feature in the two-point correlation function (TPCF) of discrete tracers such as galaxies is an accurate standard ruler. The covariance matrix…
The Stability of the BAO Linear Point under Modified Gravity
Jaemyoung Jason Lee, Bartolomeo Fiorini, Farnik Nikakhtar +1
Baryon Acoustic Oscillations (BAOs) are crucial in cosmological analysis, providing a standard ruler, as well as constraints on dark energy. In General Relativity models, the BAO L…
Displacement Field Analysis via Optimal Transport: Multi-Tracer Approach to Cosmological Reconstruction
Farnik Nikakhtar, Ravi K. Sheth, Nikhil Padmanabhan +2
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 th…
Generating synthetic star catalogs from simulated data for next-gen observatories with py-ananke
Adrien C. R. Thob, Robyn E. Sanderson, Andrew P. Eden +4
We find ourselves on the brink of an exciting era in observational astrophysics, driven by groundbreaking facilities like JWST, Euclid, Rubin, Roman, SKA, or ELT. Simultaneously, c…
Optimal Transport Reconstruction of Biased Tracers in Redshift Space
Farnik Nikakhtar, Nikhil Padmanabhan, Bruno Lévy +2
Recent research has emphasized the benefits of accurately reconstructing the initial Lagrangian positions of biased tracers from their positions at a later time, to gain cosmologic…
Building an Acceleration Ladder with Tidal Streams and Pulsar Timing
Peter Craig, Sukanya Chakrabarti, Robyn E. Sanderson +1
We analyze stellar streams in action-angle coordinates combined with recent local direct acceleration measurements to provide joint constraints on the potential of our Galaxy. Our…
Optimal Transport Reconstruction of Baryon Acoustic Oscillations
Farnik Nikakhtar, Ravi K. Sheth, Bruno Lévy +1
A weighted, semi-discrete, fast optimal transport (OT) algorithm for reconstructing the Lagrangian positions of proto-halos from their evolved Eulerian positions is presented. The…
Public data release of the FIRE-2 cosmological zoom-in simulations of galaxy formation
Andrew Wetzel, Christopher C. Hayward, Robyn E. Sanderson +23
We describe a public data release of the FIRE-2 cosmological zoom-in simulations of galaxy formation, available at http://flathub.flatironinstitute.org/fire, from the Feedback In R…
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data
Abdurro'uf, Katherine Accetta, Conny Aerts +337
This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete…
Precision Tests of CO and [CII] Power Spectra Models against Simulated Intensity Maps
Azadeh Moradinezhad Dizgah, Farnik Nikakhtar, Garrett K. Keating +1
Line intensity mapping (LIM) is an emerging technique with a unique potential to probe a wide range of scales and redshifts. Realizing the full potential of LIM, however, relies on…
The smearing scale in Laguerre reconstructions of the correlation function
Farnik Nikakhtar, Ravi K. Sheth, Idit Zehavi
To a good approximation, on large cosmological scales the evolved two-point correlation function of biased tracers is related to the initial one by a convolution. For Gaussian init…
Laguerre reconstruction of the BAO feature in halo-based mock galaxy catalogues
Farnik Nikakhtar, Ravi K. Sheth, Idit Zehavi
Fitting half-integer generalized Laguerre functions to the evolved, real-space dark matter and halo correlation functions provides a simple way to reconstruct their initial shapes.…
New families in our Solar neighborhood: applying Gaussian Mixture models for objective classification of structures in the Milky Way and in simulations
Farnik Nikakhtar, Robyn E. Sanderson, Andrew Wetzel +10
The standard picture of galaxy formation motivates the decomposition of the Milky Way into 3--4 stellar populations with distinct kinematic and elemental abundance distributions: t…
Laguerre reconstruction of the correlation function on Baryon Acoustic Oscillation scales
Farnik Nikakhtar, Ravi K. Sheth, Idit Zehavi
The baryon acoustic oscillation feature can be used as a standard cosmological ruler. In practice, for sub-percent level accuracy on the distance scale, it must be standardized. Th…