Download or read book Simulating Large Cosmology Surveys with Calibrated Halo Models written by Stuart Lynn and published by . This book was released on 2011 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis I present a novel method for constructing large scale mock galaxy and halo catalogues and apply this model to a number of important topics in modern cosmology. Traditionally such mocks are created through first evolving a high resolution particle simulation from a set of initial conditions to the present epoch, identifying bound structures and their evolution, and finally applying a semi-analytic prescription for galaxy formation. In contrast to this computationally expensive procedure, I use low resolution simulations to obtain a density field that traces large scale modes. From this background I sample the population statistics of halos: the number of halos which are typically found within a region of a given overdensity, to produce a halo catalogue. From the halo catalogue I then produce galaxies by appealing to the halo model. In this model the expected number of galaxies within a halo and the distribution of their properties is dependent on halo mass alone. By sampling conditional luminosity functions for a number of populations of galaxies, I produce a galaxy catalogue with luminosity and colour properties. The aim of developing algorithm is not to probe the mechanics of galaxy formation in great detail. It is instead intended as a method of rapidly producing mock galaxy and halo catalogues rapidly on modern desktop computers. The approach we will take is to try to distill the minimal algorithm required to achieve this and still provide useful catalogues for observational cosmologists. Both the conditional mass function and conditional luminosity functions required for the algorithm are calibrated from the Millennium Simulation, one of the highest resolution cosmology simulations to date, and its associated semi-analytic catalogues. In Chapter 2 I examine these statistics and provide fits to the quantities of interest. As a test of the method, in Chapter 3 I produce a halo and galaxy catalogue from the same large scale modes as the Millennium Simulation. The clustering statistics of galaxies and halos within this re-simulation are calculated and compared with those of the original. Con dent of the accuracy of the method, in Chapter 4 I populate a number of simulations, each 8 times the volume of the Millennium Simulation, and study the evolution of the Baryon Acoustic Oscillation signal. For each population (dark matter, halos and galaxies) I fit the BAO in the power spectrum to obtain the shift in the BAO peak. In Chapter 5 I extend the algorithm to produce lightcones: simulated skies in which the evolution of the Universe along the line of sight is accounted for. I simulate the geometry and limitations of a major pending survey and calculate the expected clustering signature I expect to see in both. The redshift space distortions induced by peculiar velocities of galaxies along the line of sight are determined and their ability to distinguish between gravity models is also explored. In Chapter 6 I detail a further extension to the algorithm for simulating weak gravitational lensing surveys. I use the analytic 2D surface density pro files of NFW profiles to dress each dark matter halo on a lightcone. The sum of these pro files over the entire population can be used to construct high resolution maps of the convergence. From these maps I calculate the spectrum of the convergence and compare with theoretical predictions. Finally in Chapter 7 I discuss further possible applications and extensions of the algorithm I have developed in this thesis.
Download or read book Simulating Large Cosmology Surveys with Calibrated Halo Models written by Stuart Lynn and published by . This book was released on 2009 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precision Cosmology with Galaxy Cluster Surveys written by Hao-Yi Wu and published by Stanford University. This book was released on 2011 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: The acceleration of the universe, which is often attributed to "dark energy, " has posed one of the main challenges to fundamental physics. Galaxy clusters provide one of the most sensitive probes of dark energy because their abundance reflects the growth rate of large-scale structure and the expansion rate of the universe. Several large galaxy cluster surveys will soon provide tremendous statistical power to constrain the properties of dark energy; however, the constraining power of these surveys will be determined by how well systematic errors are controlled. Of these systematic errors, the dominant one comes from inferring cluster masses using observable signals of clusters, the so-called "observable--mass distribution." This thesis focuses on extracting dark energy information from forthcoming large galaxy cluster surveys, including how we maximize the cosmological information, how we control important systematics, and how precisely we need to calibrate theoretical models. We study how multi-wavelength follow-up observations can improve cluster mass calibration in optical surveys. We also investigate the impact of theoretical uncertainties in calibrating the spatial distributions of galaxy clusters on dark energy constraints. In addition, we explore how the formation history of galaxy clusters impacts the self-calibration of cluster mass. In addition, we use N-body simulations to develop a new statistical sample of cluster-size halos in order to further understand the observable--mass distribution. We study the completeness of subhalos in our cluster sample by comparing them with the satellite galaxies in the Sloan Digital Sky Survey. We also study how subhalo selections impact the inferred correlation between formation time and optical mass tracers, including cluster richness and velocity dispersion.
Download or read book Models of the Galaxy and the Massive Spectroscopic Stellar Survey RAVE written by Tilmann Piffl and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulations of galaxy formation and observational Galactic Astronomy are two fields of research that study the same objects from different perspectives. Simulations try to understand galaxies like our Milky Way from an evolutionary point of view while observers try to disentangle the current structure and the building blocks of our Galaxy. Due to great advances in computational power as well as in massive stellar surveys we are now able to compare resolved stellar populations in simulations and in observations. In this thesis we use a number of approaches to relate the results of the two fields to each other. The major observational data set we refer to for this work comes from the Radial Velocity Experiment (RAVE), a massive spectroscopic stellar survey that observed almost half a million stars in the Galaxy. In a first study we use three different models of the Galaxy to generate synthetic stellar surveys that can be directly compared to the RAVE data. To do this we evaluate the RAVE selection function to great detail. Among the Galaxy models is the widely used Besancon model that performs well when individual parameter distribution are considered, but fails when we study chemodynamic correlations. The other two models are based on distributions of mass particles instead of analytical distribution functions. This is the first time that such models are converted to the space of observables and are compared to a stellar survey. We show that these models can be competitive and in some aspects superior to analytic models, because of their self-consistent dynamic history. In the case of a full cosmological simulation of disk galaxy formation we can recover features in the synthetic survey that relate to the known issues of the model and hence proof that our technique is sensitive to the global structure of the model. We argue that the next generation of cosmological galaxy formation simulations will deliver valuable models for our Galaxy. Testing these models with our approach will provide a direct connection between stellar Galactic astronomy and physical cosmology. In the second part of the thesis we use a sample of high-velocity halo stars from the RAVE data to estimate the Galactic escape speed and the virial mass of the Milky Way. In the course of this study cosmological simulations of galaxy formation also play a crucial role. Here we use them to calibrate and extensively test our analysis technique. We find the local Galactic escape speed to be 533 (+54/-41) km/s (90% confidence). With this result in combination with a simple mass model of the Galaxy we then construct an estimate of the virial mass of the Galaxy. For the mass profile of the dark matter halo we use two extreme models, a pure Navarro, Frenk & White (NFW) profile and an adiabatically contracted NFW profile. When we use statistics on the concentration parameter of these profile taken from large dissipationless cosmological simulations we obtain an estimate of the virial mass that is almost independent of the choice of the halo profile. For the mass M_340 enclosed within R_340 = 180 kpc we find 1.3 (+0.4/-0.3) x 10^12 M_sun. This value is in very good agreement with a number of other mass estimates in the literature that are based on independent data sets and analysis techniques. In the last part of this thesis we investigate a new possible channel to generate a population of Hypervelocity stars (HVSs) that is observed in the stellar halo. Commonly, it is assumed that the velocities of these stars originate from an interaction with the super-massive black hole in the Galactic center. It was suggested recently that stars stripped-off a disrupted satellite galaxy could reach similar velocities and leave the Galaxy. Here we study in detail the kinematics of tidal debris stars to investigate the probability that the observed sample of HVSs could partly originate from such a galaxy collision. We use a suite of $N$-body simulations following the encounter of a satellite galaxy with its Milky Way-type host galaxy. We quantify the typical pattern in angular and phase space formed by the debris stars and develop a simple model that predicts the kinematics of stripped-off stars. We show that the distribution of orbital energies in the tidal debris has a typical form that can be described quite accurately by a simple function. The main parameters determining the maximum energy kick a tidal debris star can get is the initial mass of the satellite and only to a lower extent its orbit. Main contributors to an unbound stellar population created in this way are massive satellites (M_sat > 10^9 M_sun). The probability that the observed HVS population is significantly contaminated by tidal debris stars appears small in the light of our results
Download or read book Constraining Cosmology with the Halo Occupation Distribution written by Jeremy L. Tinker and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The bias of galaxies with respect to the underlying matter distribution has long been an obstacle to constraining cosmology from measurements of galaxy clustering. Recent advancements in quantifying bias have made it possible to model galaxy clustering from linear to strongly non-linear scales, creating unique methods through which to constrain cosmological parameters that are complementary to more standard, large-scale techniques. These advances are encapsulated in the Halo Occupation Distribution (HOD), in which the bias of galaxies is described at the level of individual dark matter halos. For a given cosmological model, the parameters that specify the number of galaxies that reside in each halo can be constrained by measurements of the galaxy correlation function. With these HOD parameters, the given cosmology model can be tested through a number of other clustering measures that are more sensitive to the underlying dark matter distribution. The clustering measures I investigate in this thesis are mass-to-light ratios, redshift-space distortions, and galaxy void statistics. Mass-to-light ratios of galaxy clusters are uniquely suited to the halo occupation approach because the HOD can specify the number of galaxies in a halo as a function of luminosity. Galaxy bias directly influences the amount of light per unit mass in a cosmological model. I combine HOD models with observational measurements of cluster M/L ratios to test varying cosmologies. Using the HOD to model galaxy clustering in redshift-space allows one to combine data from small and large scales to break the degeneracies that govern the application of models based on linear theory alone. I use numerical simulations to calibrate a new analytic model and apply this model to observations of the redshift-space correlation function from the Sloan Digital Sky Survey. Galaxy voids prove to be insensitive to the details of halo occupation or the cosmological model assumed. This makes void statistics a sensitive test for the underlying assumption of the HOD, which states that galaxy occupation is a function of halo mass only, and not dependent on larger-scale environment. Quantifying the limits of this assumption are necessary for confidence in the constraints the HOD places on cosmology, and for testing our current picture of galaxy formation.
Download or read book Simulations of Dark Energy Cosmologies written by Elise Jennings and published by Springer Science & Business Media. This book was released on 2012-05-27 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major outstanding problem in physics is understanding the nature of the dark energy that is driving the accelerating expansion of the Universe. This thesis makes a significant contribution by demonstrating, for the first time, using state-of-the-art computer simulations, that the interpretation of future galaxy survey measurements is far more subtle than is widely assumed, and that a major revision to our models of these effects is urgently needed. The work contained in the thesis was used by the WiggleZ dark energy survey to measure the growth rate of cosmic structure in 2011 and had a direct impact on the design of the surveys to be conducted by the European Space Agency's Euclid mission, a 650 million euro project to measure dark energy.
Download or read book Precision Cosmology with Galaxy Cluster Surveys written by Hao-Yi Wu and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The acceleration of the universe, which is often attributed to "dark energy, " has posed one of the main challenges to fundamental physics. Galaxy clusters provide one of the most sensitive probes of dark energy because their abundance reflects the growth rate of large-scale structure and the expansion rate of the universe. Several large galaxy cluster surveys will soon provide tremendous statistical power to constrain the properties of dark energy; however, the constraining power of these surveys will be determined by how well systematic errors are controlled. Of these systematic errors, the dominant one comes from inferring cluster masses using observable signals of clusters, the so-called "observable--mass distribution." This thesis focuses on extracting dark energy information from forthcoming large galaxy cluster surveys, including how we maximize the cosmological information, how we control important systematics, and how precisely we need to calibrate theoretical models. We study how multi-wavelength follow-up observations can improve cluster mass calibration in optical surveys. We also investigate the impact of theoretical uncertainties in calibrating the spatial distributions of galaxy clusters on dark energy constraints. In addition, we explore how the formation history of galaxy clusters impacts the self-calibration of cluster mass. In addition, we use N-body simulations to develop a new statistical sample of cluster-size halos in order to further understand the observable--mass distribution. We study the completeness of subhalos in our cluster sample by comparing them with the satellite galaxies in the Sloan Digital Sky Survey. We also study how subhalo selections impact the inferred correlation between formation time and optical mass tracers, including cluster richness and velocity dispersion.
Download or read book Cosmological Simulations for Precision Dark Energy Measurements with Wide Field Galaxy Surveys written by Joseph William DeRose and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Current and upcoming cosmological surveys are turning their eyes towards the late time universe in an attempt to answer fundamental questions about its composition and the physical laws that govern it. Given the non-linear nature of the observables studied by these surveys, perturbative modeling approaches have limited faculty. Thus, non-perturbative simulation approaches are necessary in order to connect theory with observation and harness the statistical power contained in the deluge of data that will be collected in the coming years. In this thesis, I discuss a number of efforts, all centered around using simulations to interpret data and aid analyses with wide field galaxy surveys. The first part of this thesis will focuses on a model for galaxy formation based on the evolution of dark matter halos and subhalos in high resolution N-body simulations, and its extension to large volume, low resolution lightcone simulations. I then show the application of this model to the Dark Energy Survey (DES), the most precise weak lensing survey to date. In particular, I present the suite of simulations that I created with this model and show that it agrees well with the first year of DES (DES Y1) data. I will then demonstrate how this suite was used to test the analysis choices made in the DES Y1 analysis of weak lensing and galaxy clustering. Finally, I discuss an effort to use cosmological simulations as models for highly non-linear observables in galaxy surveys. First I will present a well validated suite of simulations suitable for this type of modeling, which efficiently spans a large cosmological parameter space. I will then overview the models that we built from these simulations, and the outlook for applying them to upcoming data in order to use it to its fullest capacity.
Download or read book Mocking the Universe written by George Frazer Stein and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Efficient generation of accurate mock observations of the sky, tailored specifically to near-future large-scale structure and cosmic microwave background surveys, is a key technical challenge in cosmology. The increasing sensitivity and sky coverage of modern surveys probe unprecedentedly-large cosmological volumes, and when coupled with increases to angular resolution, demand simulations that are accurate to smaller scales, yet cover larger volumes, than ever before. The applications of such simulations are numerous, from performing cosmological parameter analysis, to optimizing survey designs and testing analysis pipelines, to making theoretical predictions, but to adequately perform these tasks requires state-of-the-art accuracy and computational efficiency. In this thesis we develop numerical simulations of cosmological structure formation to create synthetic observations, or mocks, of current and near-future cosmic microwave background and large-scale structure surveys. We first present our development and rigorous validation of the mass-Peak Patch method, a simulation technique to rapidly generate the large-scale structure of cosmological volumes for a fraction of the computational cost of alternative methods. Mass-Peak Patch is then used in union with a number of astrophysical sky models to produce the Websky extragalactic CMB simulations, a publicly released set of synthetic mocks of the extragalactic microwave to infrared sky. Next, we focus on the up-and-coming field of intensity mapping. We construct a suite of carbon monoxide line intensity maps, and use these to forecast the constraints on the CO luminosity function with near-future observations. Both the large data volumes and complicated statistical evaluations involved in standard cosmological analyses of survey data has recently led to the adoption of many machine learning methods throughout the field, and we finish this thesis with an investigation of machine learning methods in cosmology. We first overview machine learning in cosmology and discuss the viability and attractiveness of recently-popularized deep learning techniques, and then construct, train, and validate a convolutional neural network for the purpose of aiding cosmological simulations. Efficient simulation tools such as mass-Peak Patch, accurate mocks such as the Websky extragalactic maps, and machine learning techniques (when applied correctly), will enable precision analysis of the next generation of cosmological data sets.
Download or read book Probing Cosmic Dark Matter and Dark Energy with Weak Gravitational Lensing Statistics written by Masato Shirasaki and published by Springer. This book was released on 2015-11-18 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book the applicability and the utility of two statistical approaches for understanding dark energy and dark matter with gravitational lensing measurement are introduced. For cosmological constraints on the nature of dark energy, morphological statistics called Minkowski functionals (MFs) to extract the non-Gaussian information of gravitational lensing are studied. Measuring lensing MFs from the Canada–France–Hawaii Telescope Lensing survey (CFHTLenS), the author clearly shows that MFs can be powerful statistics beyond the conventional approach with the two-point correlation function. Combined with the two-point correlation function, MFs can constrain the equation of state of dark energy with a precision level of approximately 3–4 % in upcoming surveys with sky coverage of 20,000 square degrees. On the topic of dark matter, the author studied the cross-correlation of gravitational lensing and the extragalactic gamma-ray background (EGB). Dark matter annihilation is among the potential contributors to the EGB. The cross-correlation is a powerful probe of signatures of dark matter annihilation, because both cosmic shear and gamma-ray emission originate directly from the same dark matter distribution in the universe. The first measurement of the cross-correlation using a real data set obtained from CFHTLenS and the Fermi Large Area Telescope was performed. Comparing the result with theoretical predictions, an independent constraint was placed on dark matter annihilation. Future lensing surveys will be useful to constrain on the canonical value of annihilation cross section for a wide range of mass of dark matter annihilation. Future lensing surveys will be useful to constrain on the canonical value of annihilation cross section for a wide range of mass of dark matter.
Download or read book Large Scale Structure of the Universe written by Kana Moriwaki and published by Springer Nature. This book was released on 2022-11-01 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Line intensity mapping (LIM) is an observational technique that probes the large-scale structure of the Universe by collecting light from a wide field of the sky. This book demonstrates a novel analysis method for LIM using machine learning (ML) technologies. The author develops a conditional generative adversarial network that separates designated emission signals from sources at different epochs. It thus provides, for the first time, an efficient way to extract signals from LIM data with foreground noise. The method is complementary to conventional statistical methods such as cross-correlation analysis. When applied to three-dimensional LIM data with wavelength information, high reproducibility is achieved under realistic conditions. The book further investigates how the trained machine extracts the signals, and discusses the limitation of the ML methods. Lastly an application of the LIM data to a study of cosmic reionization is presented. This book benefits students and researchers who are interested in using machine learning to multi-dimensional data not only in astronomy but also in general applications.
Download or read book Dark Matter and Dark Energy written by Sabino Matarrese and published by Springer Science & Business Media. This book was released on 2011-02-10 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together reviews from leading international authorities on the developments in the study of dark matter and dark energy, as seen from both their cosmological and particle physics side. Studying the physical and astrophysical properties of the dark components of our Universe is a crucial step towards the ultimate goal of unveiling their nature. The work developed from a doctoral school sponsored by the Italian Society of General Relativity and Gravitation. The book starts with a concise introduction to the standard cosmological model, as well as with a presentation of the theory of linear perturbations around a homogeneous and isotropic background. It covers the particle physics and cosmological aspects of dark matter and (dynamical) dark energy, including a discussion of how modified theories of gravity could provide a possible candidate for dark energy. A detailed presentation is also given of the possible ways of testing the theory in terms of cosmic microwave background, galaxy redshift surveys and weak gravitational lensing observations. Included is a chapter reviewing extensively the direct and indirect methods of detection of the hypothetical dark matter particles. Also included is a self-contained introduction to the techniques and most important results of numerical (e.g. N-body) simulations in cosmology. " This volume will be useful to researchers, PhD and graduate students in Astrophysics, Cosmology Physics and Mathematics, who are interested in cosmology, dark matter and dark energy.
Download or read book The First Galaxies in the Universe written by Abraham Loeb and published by Princeton University Press. This book was released on 2013-01-15 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive, self-contained introduction to one of the most exciting frontiers in astrophysics today: the quest to understand how the oldest and most distant galaxies in our universe first formed. Until now, most research on this question has been theoretical, but the next few years will bring about a new generation of large telescopes that promise to supply a flood of data about the infant universe during its first billion years after the big bang. This book bridges the gap between theory and observation. It is an invaluable reference for students and researchers on early galaxies. The First Galaxies in the Universe starts from basic physical principles before moving on to more advanced material. Topics include the gravitational growth of structure, the intergalactic medium, the formation and evolution of the first stars and black holes, feedback and galaxy evolution, reionization, 21-cm cosmology, and more. Provides a comprehensive introduction to this exciting frontier in astrophysics Begins from first principles Covers advanced topics such as the first stars and 21-cm cosmology Prepares students for research using the next generation of large telescopes Discusses many open questions to be explored in the coming decade
Download or read book The Effects of Halo Assembly Bias on Self Calibration in Galaxy Cluster Surveys written by and published by . This book was released on 2008 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-calibration techniques for analyzing galaxy cluster counts utilize the abundance and the clustering amplitude of dark matter halos. These properties simultaneously constrain cosmological parameters and the cluster observable-mass relation. It was recently discovered that the clustering amplitude of halos depends not only on the halo mass, but also on various secondary variables, such as the halo formation time and the concentration; these dependences are collectively termed 'assembly bias'. Applying modified Fisher matrix formalism, we explore whether these secondary variables have a significant impact on the study of dark energy properties using the self-calibration technique in current (SDSS) and the near future (DES, SPT, and LSST) cluster surveys. The impact of the secondary dependence is determined by (1) the scatter in the observable-mass relation and (2) the correlation between observable and secondary variables. We find that for optical surveys, the secondary dependence does not significantly influence an SDSS-like survey; however, it may affect a DES-like survey (given the high scatter currently expected from optical clusters) and an LSST-like survey (even for low scatter values and low correlations). For an SZ survey such as SPT, the impact of secondary dependence is insignificant if the scatter is 20% or lower but can be enhanced by the potential high scatter values introduced by a highly-correlated background. Accurate modeling of the assembly bias is necessary for cluster self-calibration in the era of precision cosmology.
Download or read book Dark Energy written by P. Ruiz-Lapuente and published by Cambridge University Press. This book was released on 2010-03-18 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: Complete and comprehensive introduction for physics graduate students just entering the field, and an authoritative reference for researchers.
Download or read book Simulations of Galaxy Formation and Large Scale Structure written by Felix Stoehr and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2009-12 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we use the N-body resimulation technique to address aspects of structure formation. In the first chapter we study the influence of the local environment of DM haloes on their properties. In the second chapter we address the so-called "substructure problem" which is one of the major challenges of the CDM model of cosmology. We perform ultra-high resolution simulations of the assembly of a Milky Way type dark matter halo within its full cosmological context and propose a new analytical fitting formula (SWTS) which provides a better fit to the simulated Milky Way halo than the NFW or Moore profiles do. In the third chapter we use our ultra-high resolution simulations to study the possible -ray signal from dark matter annihilation. If such a signal was detected, the nature of the dark matter, the answer to one of the most important questions of modern cosmology, would be known. (urn: nbn: de: bvb:19-16446)"
Download or read book Testing Gravity with Cosmology written by Georgios Valogiannis and published by . This book was released on 2020 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the era of precision cosmology, a wide range of cosmological surveys, such as the LSST, DESI, Euclid and WFIRST will precisely probe the large-scale structure of the universe, shedding light on the nature of the dark sectors. Given how sensitively the growth of structure depends on the nature of the underlying gravitational field, this will be a unique opportunity to constrain the so-called Modified Gravity models (MG), that are theoretical alternatives to dark energy, which attempt to explain cosmic acceleration through a large-scale modification to General Relativity. In order to fully utilize the wealth of incoming data, however, theoretical predictions of structure formation in such alternative scenarios are necessary. Due to the existence of an additional degree of freedom that these models introduce, N-body simulations prove to be highly computationally expensive. In the first chapter of this thesis, we discuss how we can overcome this issue by using Lagrangian hybrid techniques, which can lead to a speed-up by 2 orders of magnitude, compared to the conventional tools, while still achieving % level of accuracy. Then, in chapter 2 we proceed to introduce novel statistics that can help us more confidently detect MG signals hidden in cosmic density fields, by up-weighting the significance of cosmic voids, where the MG-LambdaCDM degeneracy is broken. In the scales where structure formation is analytically tractable, finally, we show that we can make accurate analytical predictions for the two-point statistics of halos in MG, using Lagrangian perturbation theory and the Gaussian Streaming Model, simultaneously capturing, for the first time in modified gravity, the effects of both halo-bias (in chapter 3) and redshift space distortions (in chapter 4), effects crucial for the interpretation of photometric and spectroscopic observations. Our results demonstrate that a series of analytical, semi-analytical and simulation-based tools can be utilized in order to dramatically improve our understanding of the nature of cosmic acceleration and gravity at cosmic scales.
