Nihar Gupte
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nihar-gupte.bsky.social
Nihar Gupte
@nihar-gupte.bsky.social
220 followers 100 following 38 posts
PhD student at the Max Planck for Gravitational Physics in Potsdam and University of Maryland. Working on ML for Gravitational waves and astrophysical populations.

Trying to summarize that papers I read
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nihar-gupte.bsky.social
Nihar Gupte @nihar-gupte.bsky.social · Nov 22
Now that I’m here let show off my poster! In this paper we found evidence for eccentricity in Binary Black holes observed by LIGO-Virgo-KAGRA. You can read the paper here: arxiv.org/abs/2404.14286 and my Twitter summary here: x.com/nihar_gupte/...
Reposted by Nihar Gupte
hyperbolly.bsky.social
How much information can we gain by pushing numerical relativity to its limit by simulating black hole scattering encounters? My latest paper (below) explores these extreme regions of the black-hole scattering parameter space using simulations generated using the Spectral Einstein Code (SpEC).
Black-hole scattering with numerical relativity: Self-force extraction and post-Minkowskian validation
The asymptotic nature of unbound binary-black-hole encounters provides a clean method for comparing different approaches for modeling the two-body problem in general relativity. In this work, we use n...
arxiv.org
November 16, 2025 at 11:30 AM
Reposted by Nihar Gupte
cplberry.bsky.social
Oo! Interesting #GravitationalWave candidate #S251112cm potentially from a *subsolar* mass source

If real, the source is probably has chirp mass ~0.1–0.87 solar masses

False alarm rate 1 in 6.2 yr
GraceDB gracedb.ligo.org/superevents/...
GCN gcn.nasa.gov/circulars/42...
Rating 📏🍬

[🧪🔭⚛️]
Initial sky localization. 90% area 1,200 sq deg. Initial three-dimensional volume localization. Distance around 96 Mpc.
November 12, 2025 at 6:29 PM
nihar-gupte.bsky.social
Great set of talks/panels today by Kip Thorne, Thibault Damour, Zvi Bern, Dennis Lehmkuhl, Leor Barack, Luc Blanchet, Gerhard Schäfer, and Clifford Will about the history of the two body problem. At the MPI for Grav. Phys. in Potsdam.
October 20, 2025 at 6:51 PM
nihar-gupte.bsky.social
Made a poster for a conference!
October 9, 2025 at 8:53 PM
Reposted by Nihar Gupte
physlynch.bsky.social
New paper on the arXiv today about systematic errors when modelling the gravitation waveform from extreme mass ratio inspirals and their impact on LISA data science

Huge thanks to my collaborators, especially Hassan Khalvati, for getting this project over the line! 🧪⚛️🔭🧮

arxiv.org/abs/2509.08875
A posting on the arXiv preprint server. Title: Systematic errors in fast relativistic waveforms for Extreme Mass Ratio Inspirals Authors: Hassan Khalvati, Philip Lynch, Ollie Burke, Lorenzo Speri, Maarten van de Meent, Zachary Nasipak Abstract: Accurate modeling of Extreme Mass-Ratio Inspirals (EMRIs) is essential for extracting reliable information from future space-based gravitational wave observatories. Fast waveform generation frameworks adopt an offline/online architecture, where expensive relativistic computations (e.g. self-force and black hole perturbation theory) are performed offline, and waveforms are generated rapidly online via interpolation across a multidimensional parameter space. In this work, we investigate potential sources of error that result in systematic bias in these relativistic waveform models, focusing on radiation-reaction fluxes. Two key sources of systematics are identified: (i) the intrinsic inaccuracy of the flux data, for which we focus on the truncation of the multipolar mode sum, and (ii) interpolation errors from transitioning to the online stage. We quantify the impact of mode-sum truncation and analyze interpolation errors by using various grid structures and interpolation schemes. For circular orbits in Kerr spacetime with spins larger than a≥0.9, we find that ℓmax≥30 is required for the necessary accuracy. We also develop an efficient Chebyshev interpolation scheme, achieving the desired accuracy level with significantly fewer grid points compared to spline-based methods. For circular orbits in Kerr spacetimes, we demonstrate via Bayesian studies that interpolating the flux to a maximum global relative error that is equal to the small mass ratio is sufficient for parameter estimation purposes. For 4-year long quasi-circular EMRI signals with SNRs=O(100) and mass-ratios 10^−4−10^−6, a global relative error of 10−6 yields mismatches <10^−3 and negligible parameter estimation biases.
September 12, 2025 at 4:47 PM
Reposted by Nihar Gupte
carlrodriguez.bsky.social
Ok, there's a lot of cool stuff in the new @ligo.org collaboration paper (and I'll let the actual LVK members talk about most of it), but one very cool thing from the populations paper (arxiv.org/abs/2508.18083) that jumps out to me is this plot of the effective spin for 30-40 solar mass BHs: 🔭🧪
top panel of figure 13 from the LVK populations paper (linked in post)
August 26, 2025 at 1:30 PM
nihar-gupte.bsky.social
Everyone is saying it looks like a phoenix I feel like it looks more like a butterfly or a moth from a top down view

The beak of the phoenix/antenna of the moth is the heaviest one we've seen so far, and by a good bit!
ligo.org LIGO Scientific Collaboration @ligo.org · Aug 26
Results from the first part of our fourth LIGO @egovirgo.bsky.social KAGRA observing run are out today!

We're pleased to share the largest catalog of gravitational-wave observations with more discoveries of black holes and neutron stars

📰 arxiv.org/abs/2508.18082

🔭🧪⚛️☄️ #GWTC4
New masses in the stellar graveyard plot, showing astronomical observations of black holes and neutron stars. The number of gravitational-wave observations of black holes is overwhelming. The plot is arranged to look nice, the horizontal axis has no meaning, but the vertical one shows masses. We have a significant range of masses from about 1 solar mass to over 200 solar masses for our largest merger remnant. New out today is a neutron star black hole binary GW230518_125908, as well as a lot of binary black holes.
August 26, 2025 at 4:48 PM
nihar-gupte.bsky.social
An interesting talk today at #gramaldi #amaldi16 by Gautam Satishchandran on how black holes cause decoherence of quantum experiments. The research is a thought experiment but also provides estimates on the decoherence time as a function of the distance between the experiment and the black hole.
July 17, 2025 at 7:07 PM
nihar-gupte.bsky.social
My favorite slide of the day from #gramaldi #amaldi16. Isobel Romero-Shaw talks about how we can use spin distributions and eccentricities to differentiate between field triples, isolated binary evolution and dynamical formation. It was a cool artwork as well
July 17, 2025 at 7:11 AM
nihar-gupte.bsky.social
My favorite slide today from Oliver Jennrich at #gramaldi #amaldi16. It shows how rich gravitational waves from extreme mass ratio inspirals are for testing general relativity
July 15, 2025 at 10:09 AM
Reposted by Nihar Gupte
ligo.org
We are excited to announce the discovery of #GW231123, a gravitational-wave signal from the merger of two high-mass black holes to form one about 190–265 times the mass of our Sun

ligo.org/ligo-virgo-k...

#O4IsHere 🔭🧪☄️
July 14, 2025 at 3:22 PM
nihar-gupte.bsky.social
Trump has decided he wants to kill one of humanity's most sensitive instruments for understanding the universe for... about the cost of... half a fighter jet (or less). Source: www.nasa.gov/wp-content/u...
Budget cuts to NSF projects
June 5, 2025 at 9:41 AM
Reposted by Nihar Gupte
sxs-collaboration.bsky.social
We are excited to release a major update to our catalog of binary black hole simulations, available at arxiv.org/abs/2505.13378! Such simulations are key to LIGO/Virgo/KAGRA being able to extract science from their gravitational wave detections.

1/13

🧪⚛️🔭
Figure 1 from our new catalog paper. We accurately capture precession, memory, eccentricity, and high mass ratio systems. For full details, see the paper.
May 20, 2025 at 3:13 AM
Reposted by Nihar Gupte
cplberry.bsky.social
For those with an artistic streak, #GR24Amaldi16 will be hosting an art science exhibition.

We welcome submissions inspired by the themes of the meeting (gravity, cosmology, black holes, gravitational waves, astrophysics). Anyone can submit!

uofgravity.github.io/amaldi-art/

🧪🔭🐚
Amaldi Art Show
uofgravity.github.io
May 1, 2025 at 1:32 PM
nihar-gupte.bsky.social
Wanted to shout out this paper: by @maximiliandax.bsky.social and @stephenrgreen.bsky.social. It allows us to perform parameter inference of binary neutron stars in a second. These binary neutron stars are measured with gravitational waves! Here’s a poster I made for the LVK meeting in Barcelona!
Poster showing neutron stars and the remnant kilonova. It also shows the posterior distribution of the neutron star parameters.
March 22, 2025 at 10:52 AM
Reposted by Nihar Gupte
clairelamman.bsky.social
...so is it time to throw a funeral for LCDM? That depends on who you ask 😂. It's certainly a sign that DESI's DR1 results were not a statistical fluke. Even if LCDM prevails, SOMETHING is weird and that's a great sign that we're learning something new.
March 20, 2025 at 1:06 AM
nihar-gupte.bsky.social
GOAT meets GOAT to create the GOAT of Astro YouTube series
rmcelreath.bsky.social Richard McElreath 🐈‍⬛ @rmcelreath.bsky.social · Feb 24
Part 2 is out! Continue with the epic story of how basic trigonometry (and very precise measurement) establishes the scale of the cosmos. This is much more soothing than whatever else you are scrolling. www.youtube.com/watch?v=hFMa...
February 24, 2025 at 5:50 PM
nihar-gupte.bsky.social
Wow!
emily.space Emily Hunt @emily.space · Feb 4
A very fascinating paper went up on the arXiv today!

Jesse Han & El-Badry et al. reanalysed the 21 known 'hypervelocity' stars in the #milkyway.

They find strong evidence that the LMC (Large Milky/Magellanic Cloud) has a supermassive black hole at its core! 🤯 arxiv.org/abs/2502.00102
A figure from the paper (Figure 4). It shows the locations of known hypervelocity stars as black circles, with the predicted overdensity that the LMC would cause shown in red. Full caption: Predicted on-sky overdensity of hypervelocity stars originating from a 6 × 105M⊙ supermassive black hole in the LMC. The black open circles denote the Galactic coordinates of hypervelocity stars detected in the HVS Survey, while the grey-shaded regions mark areas excluded from the survey. The current position of the LMC is illustrated with a representative image, and its orbital trajectory is drawn with a red arrow. The forward model incorporating an SMBH in the LMC along with the selection effects of the HVS Survey predicts a prominent overdensity of HVS in the region enclosed by the red contours. The overdensity arises because stars are boosted in the direction of the LMC’s orbit. This model accurately reproduces the observed overdensity location, supporting the hypothesis of an SMBH in the LMC as a source of these stars.
February 4, 2025 at 9:48 AM
Reposted by Nihar Gupte
annalenakofler.bsky.social
1/ 🌌 New Paper Alert: How can we decode the atmospheres of exoplanets efficiently and reliably?
The latest work by my amazing collaborator @timothygebhard.bsky.social introduces Flow Matching Posterior Estimation for atmospheric retrieval. 🚀🧵👇
#AI #MachineLearning #Physics #Astronomy #AcademicSky
Scientific poster with the title "Flow Matching for Atmospheric Retrieval of Exoplanets: Where Reliability meets adaptive noise levels". The background is dark with a blue exoplanet in the center and the surface of a yellow star at the bottom.
January 14, 2025 at 5:13 PM
nihar-gupte.bsky.social
I had the opportunity to answer questions at the Royal Astronomical Society (@royalastrosoc.bsky.social) about GWs+ML. Thanks to all the organizers from Royal Holloway (esp. Ann and Mattia) for inviting me!

I was able to work on this fountain pen sketch of the Victoria statue before the workshop:
A blue pen sketch of queen Victoria’s statue in front of Buckingham palace.
January 12, 2025 at 3:53 PM
nihar-gupte.bsky.social
Woke up this morning to see the sad news of the Palisades and Eaton fires. I hope everyone, their families, and pets are ok. I can't imagine what kind of anxiety it is wondering if your home is ok or not :(

Here's some info on the fires based on a project I was working on in 2019.

1/11
January 8, 2025 at 9:58 AM
nihar-gupte.bsky.social
I visited #Tokyo, #Kyoto, #Osaka, #Nara and Mt. #Fuji for ~2 weeks. #Japan, is a cool place with amazing people! I do travel sketchbooking so I thought I would share my sketches. Usually, they’re scribbled at the sites in awkward positions, but the sketches feel way more organic that way.
December 15, 2024 at 7:34 AM
nihar-gupte.bsky.social
I want to compliment the way scientists are portrayed in the Netflix series #Arcane. They're portrayed as people *first* and scientists *second*. This leads to organic motivations and character development.
December 13, 2024 at 4:58 PM
Reposted by Nihar Gupte
annalenakofler.bsky.social
1/ 🚀 New Paper Alert: Spotlight at NeurIPS ML and the Physical Sciences Workshop!
We explore the intersection of high-energy physics and machine learning. What's the challenge we’re targeting, and why does it matter? Let's dive in! 🧵👇
🚀 #AI #MachineLearning #Physics #ML4PS #NeurIPS #AcademicSky
Scientific poster with dark-blue background. Title: Flow Annealed Importance Sampling Bootstrap meets differentiable particle physics. The poster contains multiple sections: Generation of data in particle physics, normalizing flows, training approaches, and results for a 2D distribution (lambda_c^+ decay) and a 8D distribution (top production). Additionally, results for the efficiency over the number of target evaluations are shown.
December 2, 2024 at 5:40 PM