Velocity and Density Fields on Cosmological Scales

Velocity and Density Fields on Cosmological Scales PDF Author: Elena Sarpa
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
A new fully non-linear reconstruction algorithm, based on the least-action principle and extending the Fast Action Minimisation method by is presented, intended for applications with the next-generation massive spectroscopic surveys. Its capability of recovering the velocity field starting from the observed density field is tested on dark-matter halo catalogues simulation to trace the trajectories of up to 10^6 haloes backward-in-time. Both in real and redshift-space it successfully recovers the peculiar velocities. The new algorithm is first employed for the accurate recovery of the Baryonic Acoustic Oscillations (BAO) scale in two-point correlation functions. Tests on dark-matter halo catalogues show how the new algorithm successfully recovers the BAO feature in real and redshift-space, also for anomalous samples showing misplaced or absent signature of BAO. A comparison with the first-order Lagrangian reconstruction is presented, showing that this techniques outperforms the linear approximation in recovering an unbiased measurement of the BAO scale. A second version of the algorithm accounting for the survey geometry and the bias of tracers is finally tested on low-redshift galaxy samples extracted form mocks specifically designed to match the SDSS-DR12 LRG clustering. The analysis of the anisotropic clustering indicates the non-linear reconstruction as a fundamental tool to brake the degeneracy between redshift-space distortion and the Alcock-Paczynski effect. Finally the application to the cosmic voids analysis is introduced, showing the great potentiality of a non-linear modelling of the velocity field in restoring the intrinsic isotropy of voids.

Velocity and Density Fields on Cosmological Scales

Velocity and Density Fields on Cosmological Scales PDF Author: Elena Sarpa
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
A new fully non-linear reconstruction algorithm, based on the least-action principle and extending the Fast Action Minimisation method by is presented, intended for applications with the next-generation massive spectroscopic surveys. Its capability of recovering the velocity field starting from the observed density field is tested on dark-matter halo catalogues simulation to trace the trajectories of up to 10^6 haloes backward-in-time. Both in real and redshift-space it successfully recovers the peculiar velocities. The new algorithm is first employed for the accurate recovery of the Baryonic Acoustic Oscillations (BAO) scale in two-point correlation functions. Tests on dark-matter halo catalogues show how the new algorithm successfully recovers the BAO feature in real and redshift-space, also for anomalous samples showing misplaced or absent signature of BAO. A comparison with the first-order Lagrangian reconstruction is presented, showing that this techniques outperforms the linear approximation in recovering an unbiased measurement of the BAO scale. A second version of the algorithm accounting for the survey geometry and the bias of tracers is finally tested on low-redshift galaxy samples extracted form mocks specifically designed to match the SDSS-DR12 LRG clustering. The analysis of the anisotropic clustering indicates the non-linear reconstruction as a fundamental tool to brake the degeneracy between redshift-space distortion and the Alcock-Paczynski effect. Finally the application to the cosmic voids analysis is introduced, showing the great potentiality of a non-linear modelling of the velocity field in restoring the intrinsic isotropy of voids.

Implications of the Cosmological Velocity and Density Fields

Implications of the Cosmological Velocity and Density Fields PDF Author: Idit Zehavi
Publisher:
ISBN:
Category : Astronomy
Languages : en
Pages : 145

Get Book Here

Book Description


The Large-scale Density Field and Predicted Peculiar Velocity Field

The Large-scale Density Field and Predicted Peculiar Velocity Field PDF Author: Paul Jason Mancinelli
Publisher:
ISBN:
Category : Cosmology
Languages : en
Pages : 402

Get Book Here

Book Description


Cosmic Velocity Fields

Cosmic Velocity Fields PDF Author: François R. Bouchet
Publisher: Atlantica Séguier Frontières
ISBN: 9782863321423
Category : Cosmological distances
Languages : en
Pages : 638

Get Book Here

Book Description


Large-scale Density and Velocity Fields in the Universe

Large-scale Density and Velocity Fields in the Universe PDF Author: Per Vidar Barth Lilje
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description


Cosmological Physics

Cosmological Physics PDF Author: J. A. Peacock
Publisher: Cambridge University Press
ISBN: 1139935887
Category : Science
Languages : en
Pages : 700

Get Book Here

Book Description
This textbook provides advanced undergraduate and graduate students with a complete introduction to modern cosmology. It successfully bridges the gap between undergraduate and advanced graduate texts by discussing topics of current research, starting from first principles. Throughout this authoritative volume, emphasis is given to the simplest, most intuitive explanation for key equations used by researchers. The first third of the book carefully develops the necessary background in general relativity and quantum fields. The rest of the book then provides self-contained accounts of all the key topics in contemporary cosmology, including inflation, topological defects, gravitational lensing, galaxy formation, large-scale structure and the distance scale. To aid understanding, the book is well illustrated with helpful figures and includes outline solutions to nearly 100 problems. All necessary astronomical jargon is clearly explained, ensuring the book is self-contained for any student with undergraduate physics.

Cosmological Special Relativity

Cosmological Special Relativity PDF Author: Moshe Carmeli
Publisher: World Scientific
ISBN: 9810249365
Category : Science
Languages : en
Pages : 225

Get Book Here

Book Description
This book presents Einstein's theory of space and time in detail, and describes the large-scale structure of space, time and velocity as a new cosmological special relativity. A cosmological Lorentz-like transformation, which relates events at different cosmic times, is derived and applied. A new law of addition of cosmic times is obtained, and the inflation of the space at the early universe is derived, both from the cosmological transformation. The relationship between cosmic velocity, acceleration and distances is given. In the appendices gravitation is added in the form of a cosmological general relativity theory and a five-dimensional unified theory of space, time and velocity. This book is of interest to cosmologists, astrophysicists, theoretical physicists, mathematical physicists and mathematicians.

Reconstructing Cosmological Density and Velocity Fields

Reconstructing Cosmological Density and Velocity Fields PDF Author: Helen Elizabeth Mary Valentine
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description


Generation of Cosmological Large-Scale Structure

Generation of Cosmological Large-Scale Structure PDF Author: David N. Schramm
Publisher: Springer Science & Business Media
ISBN: 9400900538
Category : Science
Languages : en
Pages : 331

Get Book Here

Book Description
This volwne is the proceedings of the third school in particle astrophysics that Schramm and Galeotti have organized at Erice. The focus of thirs third school was the Generation of Cosmological Large-Scale Structure. It was held in November of 1996. The fIrst school in the series was on "Gauge Theory and the Early Universe" in May 1986, the second was on "Dark Matter in the Universe" in May 1988. All three schools have been successful under the auspices of the NATO Advanced Study Institute. This volume is thus the third in the series of the proceedings of these schools. The choice of the topic for this third school was natural, since the problem of generating a large-scale structure has become the most pressing problem in cosmology today. In particular, it is this generation of structure that is the interface between astronomical observations and particle models for the early universe. To date, all models for generating structures inevitably require new fundamental physics beyond the standard, SU x SU X U , model of high energy physics. The 3 2 I seeds for generating structures usually invoke unifIcation physics, and the matter needed to clump and form them seems to require particle properties that have not been seen in laboratories to date.

Reconstructing Cosmological Density and Velocity Fields

Reconstructing Cosmological Density and Velocity Fields PDF Author: Helen Elizabeth Mary Valentine
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description