Keshav Aggarwal
A5005302854- Analytic Number Theory Research
- Advanced Algebra and Geometry
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Finite Group Theory Research
- Algebraic Geometry and Number Theory
- Atmospheric Ozone and Climate
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Optimal Experimental Design Methods
- Spectroscopy and Laser Applications
- Advanced Mathematical Identities
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Vibration and Dynamic Analysis
- Planetary Science and Exploration
- Manufacturing Process and Optimization
- Meteorological Phenomena and Simulations
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Genetics and Plant Breeding
- Composite Structure Analysis and Optimization
- Space Exploration and Technology
- Non-Destructive Testing Techniques
- Product Development and Customization
Indian Institute of Technology Indore
2022-2024
Chandigarh University
2024
Indian Institute of Technology Delhi
2023
Chitkara University
2023
University of Maine
2019-2020
The Ohio State University
2018-2020
Narsee Monjee Institute of Management Studies
2017
Punjab Engineering College
1980-1983
Punjab Agricultural University
1972-1981
Transmission spectroscopy1-3 of exoplanets has revealed signatures water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble Spitzer Space Telescopes were hindered by observations' relatively narrow wavelength range spectral resolving power, which precluded unambiguous identification other chemical species-in particular primary carbon-bearing molecules6,7. Here we report broad-wavelength 0.5-5.5 µm atmospheric...
Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking formation evolution exoplanetary systems. Access to an exoplanet's chemical inventory requires high-precision observations, often inferred from individual molecular detections with low-resolution space-based high-resolution ground-based facilities. Here we report medium-resolution (R$\sim$600) transmission spectrum atmosphere between 3-5 $\mu$m covering multiple absorption...
Abstract Carbon dioxide (CO 2 ) is a key chemical species that found in wide range of planetary atmospheres. In the context exoplanets, CO an indicator metal enrichment (that is, elements heavier than helium, also called ‘metallicity’) 1–3 , and thus formation processes primary atmospheres hot gas giants 4–6 . It one most promising to detect secondary terrestrial exoplanets 7–9 Previous photometric measurements transiting planets with Spitzer Space Telescope have given hints presence but not...
Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability. However, no unambiguous photochemical products have been detected in exoplanet to date. Recent observations from JWST Transiting Exoplanet Early Release Science Program found spectral absorption feature at 4.05 $\mu$m arising SO$_2$ atmosphere WASP-39b. WASP-39b 1.27-Jupiter-radii, Saturn-mass (0.28 M$_J$) gas giant orbiting Sun-like star with an equilibrium temperature...
Abstract Close-in giant exoplanets with temperatures greater than 2,000 K (‘ultra-hot Jupiters’) have been the subject of extensive efforts to determine their atmospheric properties using thermal emission measurements from Hubble Space Telescope (HST) and Spitzer 1–3 . However, previous studies yielded inconsistent results because small sizes spectral features limited information content data resulted in high sensitivity varying assumptions made treatment instrument systematics retrieval...
The recent inference of sulfur dioxide (SO2) in the atmosphere hot (approximately 1,100 K), Saturn-mass exoplanet WASP-39b from near-infrared JWST observations1-3 suggests that photochemistry is a key process high-temperature atmospheres4. This because low (<1 ppb) abundance SO2 under thermochemical equilibrium compared with produced H2O and H2S (1-10 ppm)4-9. However, was made single, small molecular feature transmission spectrum at 4.05 μm and, therefore, detection other absorption bands...
Abstract Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models predict that clouds may condense on nightside molecular abundances can be driven out of equilibrium by zonal winds. Here we report a phase-resolved emission spectrum hot Jupiter WASP-43b measured from 5 μm to 12 JWST’s Mid-Infrared Instrument. The spectra reveal large day–night temperature contrast (with...
Observing exoplanets through transmission spectroscopy supplies detailed information on their atmospheric composition, physics, and chemistry. Prior to JWST, these observations were limited a narrow wavelength range across the near-ultraviolet near-infrared, alongside broadband photometry at longer wavelengths. To understand more complex properties of exoplanet atmospheres, improved coverage resolution are necessary robustly quantify influence broader absorbing molecular species. Here we...
Using data collected by the Indian Mars Orbiter Mission in October 2021, we investigated coronal regions of Sun analyzing Doppler spectral width radio signals to estimate solar wind velocity. A simplified equation is introduced directly relate these two parameters. The study focuses on observations conducted from 2 14, a relatively quiet phase cycle 25. analysis targeted region within heliocentric distances 5-8 RSun, near ecliptic plane. In this region, velocities ranged 100 150 kms^-1,...
Abstract Using data collected by the Indian Mars Orbiter Mission (MOM) in 2021 October, we investigated coronal regions of Sun analyzing Doppler spectral width radio signals to estimate solar wind velocity. A simplified equation is introduced directly relate these two parameters. The study focuses on observations conducted from October 2 14, a relatively quiet phase cycle 25. analysis targeted region within heliocentric distances 5–8 R ⊙ , near ecliptic plane. In this region, velocities...
Abstract Carbon monoxide (CO) is predicted to be the dominant carbon-bearing molecule in giant planet atmospheres and, along with water, important for discerning oxygen and therefore carbon-to-oxygen ratio of these planets. The fundamental absorption mode CO has a broad, double-branched structure composed many individual lines from 4.3 5.1 μ m, which can now spectroscopically measured JWST. Here we present technique detecting rotational sub-band at medium resolution NIRSpec G395H instrument....
Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models predict that clouds may condense on nightside molecular abundances can be driven out of equilibrium by zonal winds. Here we report a phase-resolved emission spectrum hot Jupiter WASP-43b measured from 5-12 $μ$m JWST's Mid-Infrared Instrument (MIRI). The spectra reveal large day-night temperature contrast (with...
We revisit Munshi’s proof of the [Formula: see text]-aspect subconvex bound for text] text]-functions, and we are able to remove “conductor lowering” trick. This simplification along with a more careful stationary phase analysis allows us improve
Abstract In this paper, we introduce a simple Bessel $\delta $-method to the theory of exponential sums for $\textrm{GL}_2$. Some results Jutila on are generalized in less technical manner holomorphic newforms arbitrary level and nebentypus. particular, gives short proof Weyl-type subconvex bound $t$-aspect associated $L$-functions.
Carbon dioxide (CO2) is a key chemical species that found in wide range of planetary atmospheres. In the context exoplanets, CO2 an indicator metal enrichment (i.e., elements heavier than helium, also called "metallicity"), and thus formation processes primary atmospheres hot gas giants. It one most promising to detect secondary terrestrial exoplanets. Previous photometric measurements transiting planets with Spitzer Space Telescope have given hints presence but not yielded definitive...
Close-in giant exoplanets with temperatures greater than 2,000 K (''ultra-hot Jupiters'') have been the subject of extensive efforts to determine their atmospheric properties using thermal emission measurements from Hubble and Spitzer Space Telescopes. However, previous studies yielded inconsistent results because small sizes spectral features limited information content data resulted in high sensitivity varying assumptions made treatment instrument systematics retrieval analysis. Here we...
Let $g$ be a fixed Hecke cusp form for $\mathrm{SL}(2,\mathbb{Z})$ and $\chi$ primitive Dirichlet character of conductor $M$. The best known subconvex bound $L(1/2,g\otimes \chi)$ is Burgess strength. was proved by couple methods: shifted convolution sums the Petersson/Kuznetsov formula analysis. It natural to ask what inputs are really needed prove Burgess-type on $\rm GL(2)$. In this paper, we give new proof bounds ${L(1/2,g\otimes \chi)\ll_{g,\varepsilon} M^{1/2-1/8+\varepsilon}}$...
Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability. However, no unambiguous photochemical products have been detected in exoplanet to date. Recent observations from JWST Transiting Exoplanet Early Release Science Program found spectral absorption feature at 4.05 $μ$m arising SO$_2$ atmosphere WASP-39b. WASP-39b 1.27-Jupiter-radii, Saturn-mass (0.28 M$_J$) gas giant orbiting Sun-like star with an equilibrium temperature...
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Let $M$ be a squarefree positive integer and $P$ prime number coprime to such that $P \sim M^{\eta}$ with $0 < \eta 2/5$. We simplify the proof of subconvexity bounds for $L(\frac{1]{2}, f \otimes \chi)$ when $f$ is primitive holomorphic cusp form level $\chi$ Dirichlet character modulo $M$. These are attained through an unamplified second moment method using modified version delta due R. Munshi. The technique similar used by Duke-Friedlander-Iwaniec save modification method.
We revisit Munshi's proof of the $t$-aspect subconvex bound for $\rm GL(3)$ $L$-functions, and we are able to remove `conductor lowering' trick. This simplification along with a more careful stationary phase analysis allows us improve to, $$ L(1/2+it, π) \ll_{π, ε} (1+|t|)^{3/4-3/40+ε}.