Anıl Zenginoğlu
@anilzen.bsky.social
Scientist working on waves, black holes, hyperbolic geometry, and optimization. Chasing light to infinity. Seeking resonance.
Reposted by Anıl Zenginoğlu
On the occasion of #GR24Amaldi16, all articles in the collection "Hyperboloidal foliations in the era of gravitational-wave astronomy" are free-to-read from 10 July to 10 August 2025! link.springer.com/collections/... — Don't miss today's related talks by Anna Sancassani and Benjamin Leather!
July 14, 2025 at 12:43 PM
On the occasion of #GR24Amaldi16, all articles in the collection "Hyperboloidal foliations in the era of gravitational-wave astronomy" are free-to-read from 10 July to 10 August 2025! link.springer.com/collections/... — Don't miss today's related talks by Anna Sancassani and Benjamin Leather!
I finally got it!!!
This is a finite element solution of a scattering problem using hyperboloidal compactification.
A method developed in an unknown niche corner of mathematical relativity and conformal geometry is now ready for real-world problems!
This is a finite element solution of a scattering problem using hyperboloidal compactification.
A method developed in an unknown niche corner of mathematical relativity and conformal geometry is now ready for real-world problems!
April 30, 2025 at 2:37 AM
I finally got it!!!
This is a finite element solution of a scattering problem using hyperboloidal compactification.
A method developed in an unknown niche corner of mathematical relativity and conformal geometry is now ready for real-world problems!
This is a finite element solution of a scattering problem using hyperboloidal compactification.
A method developed in an unknown niche corner of mathematical relativity and conformal geometry is now ready for real-world problems!
Achievement unlocked 🥂 🧪: Published a technical physics paper with a philosophical opening: "What is time?"
The paper addresses an aspect of this timeless question in a rather technical sense: How should we construct time in GR with its black holes and observers?
link.springer.com/article/10.1...
The paper addresses an aspect of this timeless question in a rather technical sense: How should we construct time in GR with its black holes and observers?
link.springer.com/article/10.1...
Bridging time across null horizons - General Relativity and Gravitation
General relativity, as a diffeomorphism-invariant theory, allows the description of physical phenomena in a wide variety of coordinate systems. In the presence of boundaries, such as event horizons an...
link.springer.com
April 29, 2025 at 1:58 AM
Achievement unlocked 🥂 🧪: Published a technical physics paper with a philosophical opening: "What is time?"
The paper addresses an aspect of this timeless question in a rather technical sense: How should we construct time in GR with its black holes and observers?
link.springer.com/article/10.1...
The paper addresses an aspect of this timeless question in a rather technical sense: How should we construct time in GR with its black holes and observers?
link.springer.com/article/10.1...
This is the language used for DEI in a letter from the Office for Civil Rights: "a shameful echo of a darker period in this country's history."
Times are changing.
Times are changing.
February 18, 2025 at 1:34 AM
This is the language used for DEI in a letter from the Office for Civil Rights: "a shameful echo of a darker period in this country's history."
Times are changing.
Times are changing.
In general relativity, general covariance applies only to coordinate systems related to each other by smooth transformations.
In the presence of boundaries, general covariance is explicitly broken. Gauge-fixing must consider the boundary structure.
In the presence of boundaries, general covariance is explicitly broken. Gauge-fixing must consider the boundary structure.
February 6, 2025 at 10:03 PM
In general relativity, general covariance applies only to coordinate systems related to each other by smooth transformations.
In the presence of boundaries, general covariance is explicitly broken. Gauge-fixing must consider the boundary structure.
In the presence of boundaries, general covariance is explicitly broken. Gauge-fixing must consider the boundary structure.
A horizon is a limiting surface of no return. It's the boundary beyond which interaction is impossible. We can send signals beyond the horizon but can never receive signals back.
Famously, black holes were the first relativistic horizons we discovered. The event horizon is a surface of no return. 🧪
Famously, black holes were the first relativistic horizons we discovered. The event horizon is a surface of no return. 🧪
February 6, 2025 at 12:51 PM
A horizon is a limiting surface of no return. It's the boundary beyond which interaction is impossible. We can send signals beyond the horizon but can never receive signals back.
Famously, black holes were the first relativistic horizons we discovered. The event horizon is a surface of no return. 🧪
Famously, black holes were the first relativistic horizons we discovered. The event horizon is a surface of no return. 🧪
Buying quantum computing stocks is all fun and games until you remember that Gutenberg was practically bankrupt because of his printing press.
December 29, 2024 at 6:36 PM
Buying quantum computing stocks is all fun and games until you remember that Gutenberg was practically bankrupt because of his printing press.
Reposted by Anıl Zenginoğlu
New paper the cites the BHPToolkit: "Gravitational self-force with hyperboloidal slicing and spectral methods" by Benjamin Leather, arxiv.org/abs/2411.14976
November 25, 2024 at 9:43 AM
New paper the cites the BHPToolkit: "Gravitational self-force with hyperboloidal slicing and spectral methods" by Benjamin Leather, arxiv.org/abs/2411.14976
We live in hyperbolic times. So here's a paper about hyperbolic times, fresh off the press, published just yesterday.
https://buff.ly/3OjsJi3
https://buff.ly/3OjsJi3
pubs.aip.org
November 23, 2024 at 9:04 AM
We live in hyperbolic times. So here's a paper about hyperbolic times, fresh off the press, published just yesterday.
https://buff.ly/3OjsJi3
https://buff.ly/3OjsJi3
We live in hyperbolic times indeed.
Here's a paper about hyperbolic times, fresh off the press, published just yesterday.
pubs.aip.org/aapt/ajp/art...
Here's a paper about hyperbolic times, fresh off the press, published just yesterday.
pubs.aip.org/aapt/ajp/art...
pubs.aip.org
November 22, 2024 at 4:45 PM
We live in hyperbolic times indeed.
Here's a paper about hyperbolic times, fresh off the press, published just yesterday.
pubs.aip.org/aapt/ajp/art...
Here's a paper about hyperbolic times, fresh off the press, published just yesterday.
pubs.aip.org/aapt/ajp/art...
Reposted by Anıl Zenginoğlu
Paper day! My article on counterintuitive properties of accelerated motion is out in Am. J. Phys. (It's Open Access, and also an "Editor's pick," yay!) 🧪⚛️🎢 - things like "two objects that keep a constant distance from each other can still be in non-zero relative motion!"
Counterintuitive properties of relativistic relative motion for accelerated observers
Editor's Note: Could a laser rangefinder give constant readings even though the distance between two objects is changing? Will two observers always agree about
pubs.aip.org
November 21, 2024 at 1:44 PM
Paper day! My article on counterintuitive properties of accelerated motion is out in Am. J. Phys. (It's Open Access, and also an "Editor's pick," yay!) 🧪⚛️🎢 - things like "two objects that keep a constant distance from each other can still be in non-zero relative motion!"
Reposted by Anıl Zenginoğlu
If you've got a clear view of the Eastern sky, step outside for a few minutes. There's a lovely alignment of the moon, Jupiter & Aldebaran. (a red giant 44x the diameter of the sun)
November 18, 2024 at 2:58 AM
If you've got a clear view of the Eastern sky, step outside for a few minutes. There's a lovely alignment of the moon, Jupiter & Aldebaran. (a red giant 44x the diameter of the sun)
Reposted by Anıl Zenginoğlu
Why are people who get excited about precision metrology fired up about the prospect of a clock based on thorium? (PM repost) open.substack.com/pub/chadorze...
Why Is a Thorium Clock a Big Deal?
A bit of atomic horology to start your week off right...
open.substack.com
November 18, 2024 at 9:10 PM
Why are people who get excited about precision metrology fired up about the prospect of a clock based on thorium? (PM repost) open.substack.com/pub/chadorze...
Reminder for new users here:
Quantum physics is not only the physics at small scales. There are macroscopic quantum phenomena.
Quantum physics is not only the physics at small scales. There are macroscopic quantum phenomena.
Reminder for new users here:
The spacetime metric is a Lorentzian signature tensor with precisely one negative eigenvalue
The spacetime metric is a Lorentzian signature tensor with precisely one negative eigenvalue
Reminder for new users here:
The Higgs field (see below) gives mass to fundamental particles, like the electron and the quarks in protons and neutrons. But most of the mass of protons and neutrons is due to the binding energy of the strong interaction. That thus applies to your body too.
The Higgs field (see below) gives mass to fundamental particles, like the electron and the quarks in protons and neutrons. But most of the mass of protons and neutrons is due to the binding energy of the strong interaction. That thus applies to your body too.
November 17, 2024 at 12:16 PM
Reminder for new users here:
Quantum physics is not only the physics at small scales. There are macroscopic quantum phenomena.
Quantum physics is not only the physics at small scales. There are macroscopic quantum phenomena.
Reposted by Anıl Zenginoğlu
People who study relativity like to "conformally compactify" spacetime, creating a finite patch of coordinates, and attaching a boundary. This makes it possible to talk about going to "infinity" more precisely. This turns Minkowski space into what they call a "diamond".
🧪⚛️ #🧮
🧪⚛️ #🧮
November 15, 2024 at 8:03 PM
People who study relativity like to "conformally compactify" spacetime, creating a finite patch of coordinates, and attaching a boundary. This makes it possible to talk about going to "infinity" more precisely. This turns Minkowski space into what they call a "diamond".
🧪⚛️ #🧮
🧪⚛️ #🧮
Reposted by Anıl Zenginoğlu
I'll start! I'm looking forward to seeing arxiv announcements, explainer threads, deep technical discussion happening in the comments that I don't understand, and of course overly niche shitposts
November 15, 2024 at 4:45 PM
I'll start! I'm looking forward to seeing arxiv announcements, explainer threads, deep technical discussion happening in the comments that I don't understand, and of course overly niche shitposts
Reposted by Anıl Zenginoğlu
New article: "The geometry of data: the missing metric tensor and the Stein score" (blog.christianperone.com/2024/11/the-...). I show how you can derive a (efficient to compute) data manifold metric tensor with the Stein score alone ! Deep connections to diffusion, score-based models and physics.
November 14, 2024 at 3:13 PM
New article: "The geometry of data: the missing metric tensor and the Stein score" (blog.christianperone.com/2024/11/the-...). I show how you can derive a (efficient to compute) data manifold metric tensor with the Stein score alone ! Deep connections to diffusion, score-based models and physics.
Reposted by Anıl Zenginoğlu
The Stokes phenomenon, animated! Highlighting the integration contour for evaluating an integral (for the Airy function) in the saddle point / stationary phase method. Inside the left Stokes wedge, two saddle points contribute; outside, only one (more details in alt text).
🧪 #🧮
🧪 #🧮
November 14, 2024 at 9:24 PM
The Stokes phenomenon, animated! Highlighting the integration contour for evaluating an integral (for the Airy function) in the saddle point / stationary phase method. Inside the left Stokes wedge, two saddle points contribute; outside, only one (more details in alt text).
🧪 #🧮
🧪 #🧮
Reposted by Anıl Zenginoğlu
Last week, Ollie Burke and I put out a note describing how to convert between all the different orbital phases used to describe orbits around a spinning black hole. The most fun reason to do this is. to help make visualisations like this one
arxiv.org/abs/2411.04955
arxiv.org/abs/2411.04955
November 14, 2024 at 5:45 PM
Last week, Ollie Burke and I put out a note describing how to convert between all the different orbital phases used to describe orbits around a spinning black hole. The most fun reason to do this is. to help make visualisations like this one
arxiv.org/abs/2411.04955
arxiv.org/abs/2411.04955
An interesting idea: information communication can be viewed as information storage. Sending a message across space is similar to storing it over time.
November 13, 2024 at 7:59 PM
An interesting idea: information communication can be viewed as information storage. Sending a message across space is similar to storing it over time.
Reposted by Anıl Zenginoğlu
Here's the beginning of starter pack for people and groups working on the theory, detection, or analysis of gravitational waves, or whose work is closely related to the field of gravitational waves. Please let me know who I've missed and I'll add them. go.bsky.app/HrAJX35
November 10, 2024 at 4:26 PM
Here's the beginning of starter pack for people and groups working on the theory, detection, or analysis of gravitational waves, or whose work is closely related to the field of gravitational waves. Please let me know who I've missed and I'll add them. go.bsky.app/HrAJX35
I picked up an interesting idea from a seminar by Marina De Amicis about black hole perturbations
Quasinormal modes deliver small scale information to the observer, whereas the tail delivers large scale information.
The tail is a memory effect telling you what perturbed the spacetime long time ago
Quasinormal modes deliver small scale information to the observer, whereas the tail delivers large scale information.
The tail is a memory effect telling you what perturbed the spacetime long time ago
November 10, 2024 at 4:35 PM
I picked up an interesting idea from a seminar by Marina De Amicis about black hole perturbations
Quasinormal modes deliver small scale information to the observer, whereas the tail delivers large scale information.
The tail is a memory effect telling you what perturbed the spacetime long time ago
Quasinormal modes deliver small scale information to the observer, whereas the tail delivers large scale information.
The tail is a memory effect telling you what perturbed the spacetime long time ago
One great use case of ChatGPT for me has been in making figures. These turned out pretty.
February 14, 2024 at 1:45 PM
One great use case of ChatGPT for me has been in making figures. These turned out pretty.
I wrote a technical guide on solving wave equations on unbounded domains.
The idea is to map the unbounded domain to a bounded domain.
The trick is to combine spatial mapping with a transformation of time.
Code is included in Google Colab.
anilzen.github.io/post/2023/wa...
The idea is to map the unbounded domain to a bounded domain.
The trick is to combine spatial mapping with a transformation of time.
Code is included in Google Colab.
anilzen.github.io/post/2023/wa...
December 14, 2023 at 7:43 PM
I wrote a technical guide on solving wave equations on unbounded domains.
The idea is to map the unbounded domain to a bounded domain.
The trick is to combine spatial mapping with a transformation of time.
Code is included in Google Colab.
anilzen.github.io/post/2023/wa...
The idea is to map the unbounded domain to a bounded domain.
The trick is to combine spatial mapping with a transformation of time.
Code is included in Google Colab.
anilzen.github.io/post/2023/wa...
What's the relativistic analog of a soap bubble?
It's a hyperboloid.
Soap bubbles are minimal surfaces. They minimize area to enclose a given volume of air. Similarly, hyperboloids maximize volume to enclose a given spacetime volume.
anilzen.github.io/post/2023/sp...
It's a hyperboloid.
Soap bubbles are minimal surfaces. They minimize area to enclose a given volume of air. Similarly, hyperboloids maximize volume to enclose a given spacetime volume.
anilzen.github.io/post/2023/sp...
Splitting spacetime | Anıl Zenginoğlu
Hyperboloidal hypersurfaces split spacetime into space and time. Their mathematical definition connects to a physical principle that may be useful as a mental image for the quantum foam.
anilzen.github.io
September 20, 2023 at 4:07 PM
What's the relativistic analog of a soap bubble?
It's a hyperboloid.
Soap bubbles are minimal surfaces. They minimize area to enclose a given volume of air. Similarly, hyperboloids maximize volume to enclose a given spacetime volume.
anilzen.github.io/post/2023/sp...
It's a hyperboloid.
Soap bubbles are minimal surfaces. They minimize area to enclose a given volume of air. Similarly, hyperboloids maximize volume to enclose a given spacetime volume.
anilzen.github.io/post/2023/sp...