A5015193169- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- GNSS positioning and interference
- Astrophysics and Cosmic Phenomena
- Antenna Design and Optimization
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Direction-of-Arrival Estimation Techniques
- Superconducting and THz Device Technology
- Spectroscopy and Laser Applications
- Advanced Adaptive Filtering Techniques
- Structural Health Monitoring Techniques
- Topological and Geometric Data Analysis
- Scientific Measurement and Uncertainty Evaluation
- Single-cell and spatial transcriptomics
- Artificial Immune Systems Applications
- Scientific Research and Discoveries
- Advanced Wireless Communication Techniques
- Black Holes and Theoretical Physics
- Quantum, superfluid, helium dynamics
University of Cape Town
2022-2024
University of Central Thailand
2023
National Centre for Radio Astrophysics
2016-2019
Tata Institute of Fundamental Research
2018
The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) is a radio interferometer array currently in development, with an initial 256-element to be deployed at the South African Radio Astronomy Observatory (SARAO) Square Kilometer Array (SKA) site Africa. Each of 6m, $f/0.23$ dishes will instrumented dual-polarisation feeds operating over frequency range 400-800 MHz. Through intensity mapping 21 cm emission line neutral hydrogen, HIRAX provide cosmological survey distribution...
Abstract Over the last few decades, a plethora of modifications to general relativity have been proposed solve host cosmological and astrophysical problems. Many modified gravity models are now ruled out with further observations; some theories still viable, with, at best, bounds on their parameters set by observations date. More recently, Fast Radio Bursts proven be remarkably powerful tools constrain cosmology fundamental physics. In this work, we consider generic theory implications for...
Radio Frequency Interference (RFI) is a growing concern for contemporary radio telescopes. This paper describes techniques real-time threshold-based detection and filtering of broadband narrowband RFI the correlator beamformer chains telescope back-end, with specific applications to upgraded Giant Meterwave Telescope (uGMRT). The Median Absolute Deviation (MAD) estimator used robust estimation dispersion received signal in temporal spectral domains. Results from tests carried out GMRT...
Radio Frequency Interference (RFI) excision in wideband radio telescope receivers is gaining significance due to increasing levels of manmade RFI and operation outside the protected astronomy bands. The effect on astronomical data can be significantly reduced through real-time excision. In this paper, Median Absolute Deviation (MAD) used for excising signals corrupted by strong impulsive interference. MAD estimation requires recursive median calculation which a computationally challenging...
The Giant Metrewave Radio Telescope (GMRT) is being upgraded to increase the receiver sensitivity. This makes more susceptible man-made Frequency Interference (RFI). To improve performance in presence of RFI, real-time RFI excision (filtering) incorporated GMRT wideband backend (GWB). filtering system implemented on FPGA (Field Programmable Gate Array) and CPU (Central Processing Unit)–GPU (Graphics Unit) platforms detect remove broadband narrowband respectively. detected using a...
Real-time RFI excision is developed for the GMRT wideband correlator as part of upgraded (uGMRT) project. The technique uses robust statistical estimation and a nonlinear filter to excise broadband narrowband RFI. This paper provides an overview its real-time implementation. results showing improvement in signal-to-noise ratio cross-correlation performance are also provided.
Fast radio bursts (FRBs) offer unique probes of diverse cosmological phenomena due to their characteristic properties, including short duration timescale and high dispersion measure. This study investigates two distinct theoretical frameworks: the Gertsenshtein-Zel'dovich (GZ) mechanism for ultra-high-frequency gravitational waves (GWs) fraction dark matter in primordial mass black holes. We explore hypothesis that GWs could be responsible FRB generation. Consequently, detection continuous...
Fast Radio Bursts (FRBs) are bright radio transient events, a subset of which have been localized to their host galaxies. Their high dispersion measures offer valuable insights into the ionized plasma along line sight, enabling them serve as probes cosmological parameters. One major challenges in contemporary cosmology is Hubble tension -- an unresolved discrepancy between two independent methods determining Universe's expansion rate, yielding differing values for constant. In this study, we...
Over the last few decades, a plethora of modifications to general relativity have been proposed solve host cosmological and astrophysical problems. Many modified gravity models are now ruled out with further observations; some theories still viable, with, at best, bounds on their parameters set by observations date. More recently, Fast Radio Bursts proven be remarkably powerful tools constrain cosmology fundamental physics. In this work, we consider generic theory implications for...
In this paper, we use Topological Data Analysis (TDA), a mathematical approach for studying data shape, to analyse Fast Radio Bursts (FRBs). Applying the Mapper algorithm, visualise topological structure of large FRB sample. Our findings reveal three distinct populations based on their inferred source properties, and show robust indicating morphology energy. We also identify potential non-repeating FRBs that might become repeaters proximity in graph. This work showcases TDA's promise...