A5102861953- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- Computational Physics and Python Applications
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Statistical and numerical algorithms
- Adaptive optics and wavefront sensing
- Superconducting and THz Device Technology
- Astrophysics and Cosmic Phenomena
- Chaos-based Image/Signal Encryption
- Advanced Statistical Methods and Models
- Gaussian Processes and Bayesian Inference
- Complex Systems and Time Series Analysis
- Astrophysics and Star Formation Studies
- Advanced Wireless Communication Techniques
- Stellar, planetary, and galactic studies
- Advanced Database Systems and Queries
- Statistical Methods and Bayesian Inference
- Algorithms and Data Compression
- Monetary Policy and Economic Impact
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
- Coding theory and cryptography
University of Oxford
2024
Scuola Internazionale Superiore di Studi Avanzati
2021-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2023-2024
Istituto Nazionale di Fisica Nucleare
2023-2024
Abstract We present a formalism to extract the angular power spectrum of fields sampled at finite number points with arbitrary positions — common situation for several catalog-based astrophysical probes through simple extension standard pseudo- C ℓ algorithm. A key complication in this case is need handle shot noise component associated discrete mask which, sparse catalogs, can lead strong coupling between very different scales. show that problem be solved easily by estimating contribution...
The upcoming Simons Observatory Small Aperture Telescopes aim at achieving a constraint on the primordial tensor-to-scalar ratio $r$ level of $\sigma(r=0)\lesssim0.003$, observing polarized CMB in presence partial sky coverage, cosmic variance, inhomogeneous non-white noise, and Galactic foregrounds. We present three different analysis pipelines able to constrain given latest available instrument performance, compare their predictions set simulations that allow us explore number foreground...
The analysis of photometric large-scale structure data is often complicated by the need to account for many observational and astrophysical systematics. elaborate models needed describe them introduce "nuisance parameters'', which can be a major inhibitor an efficient parameter inference. In this paper we approximate method analytically marginalise over large number nuisance parameters based on Laplace approximation. We discuss mathematics method, its relation concepts such as volume effects...
We present a transfer function-based method to estimate angular power spectra from filtered maps for cosmic microwave background (CMB) surveys. This is especially relevant experiments targeting the faint primordial gravitational wave signatures in CMB polarisation at large scales, such as Simons Observatory (SO) small aperture telescopes. While timestreams can be mitigate contamination low-frequency noise, usual methods that calculate mode coupling individual multipoles challenging covering...
Observing in six frequency bands from 27 to 280 GHz over a large sky area, the Simons Observatory (SO) is poised address many questions Galactic astrophysics addition its principal cosmological goals. In this work, we provide quantitative forecasts on astrophysical parameters of interest for range science cases. We find that SO can: constrain spectrum polarized dust emission at level $\Delta\beta_d \lesssim 0.01$ and thus test models composition predict $\beta_d$ polarization differs...
We use time-domain simulations of Jupiter observations to test and develop a beam reconstruction pipeline for the Simons Observatory Small Aperture Telescopes. The method relies on map maker that estimates subtracts correlated atmospheric noise fitting code designed compensate bias caused by maker. our performance four different frequency bands against various algorithmic parameters, conditions input beams. additionally show quality as function number available investigate how calibration...
The Simons Observatory (SO), due to start full science operations in early 2025, aims set tight constraints on inflationary physics by inferring the tensor-to-scalar ratio <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>r</a:mi></a:math> from measurements of cosmic microwave background (CMB) polarization <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>B</c:mi></c:math>-modes. Its nominal design including three small-aperture telescopes...
The analysis of photometric large-scale structure data is often complicated by the need to account for many observational and astrophysical systematics. elaborate models needed describe them introduce ``nuisance parameters'', which can be a major inhibitor an efficient parameter inference. In this paper we approximate method analytically marginalise over large number nuisance parameters based on Laplace approximation. We discuss mathematics method, its relation concepts such as volume...
The Simons Observatory (SO), a next-generation ground-based CMB experiment in its final stages of construction, will target primordial $B$-modes with unprecedented sensitivity to set tight bounds on the amplitude inflationary gravitational waves. Aiming infer tensor-to-scalar ratio $r$ precision $\sigma(r=0) \leq 0.003$, SO rely powerful component-separation algorithms distinguish faint signal from stronger sources large-scale such as Galactic foregrounds and weak lensing. We present an...
The optical depth to reionization, $\tau$, is the least constrained parameter of cosmological $\Lambda$CDM model. To date, its most precise value inferred from large-scale polarized CMB power spectra ${\it Planck}$ High-Frequency Instrument (HFI). These maps are known contain significant contamination by residual non-Gaussian systematic effects, which hard model analytically. Therefore, robust constraints on $\tau$ currently obtained through an empirical cross-spectrum likelihood built...
The ratio of Bayesian evidences is a popular tool in cosmology to compare different models. There are however several issues with this method: Bayes' factor depends on the prior even limit noninformative priors, and Jeffreys scale, used assess test, arbitrary. Moreover, standard use often criticized for being unable reject In paper, we address these shortcoming by promoting evidence ratios frequentist statistics deriving their sampling distributions. By comparing distributions, poor fitting...
We present a formalism to extract the angular power spectrum of fields sampled at finite number points with arbitrary positions -- common situation for several catalog-based astrophysical probes through simple extension standard pseudo-$C_\ell$ algorithm. A key complication in this case is need handle shot noise component associated discrete mask which, sparse catalogs, can lead strong coupling between very different scales. show that problem be solved easily by estimating contribution...
The optical depth to reionization, $τ$, is the least constrained parameter of cosmological $Λ$CDM model. To date, its most precise value inferred from large-scale polarized CMB power spectra $\textit{Planck}$ High-Frequency Instrument (HFI). These maps are known contain significant contamination by residual non-Gaussian systematic effects, which hard model analytically. Therefore, robust constraints on $τ$ currently obtained through an empirical cross-spectrum likelihood built simulations....
Near-field radio holography is a common method for measuring and aligning mirror surfaces millimeter sub-millimeter telescopes. In instruments with more than single mirror, degeneracies arise in the measurement, requiring multiple measurements new fitting methods. We present HoloSim-ML, Python code beam simulation analysis of data from complex optical systems. This uses machine learning to efficiently determine position hundreds adjusters on mirrors few micron accuracy. apply this approach...