Ulrich Pennig
@pennigulrich.bsky.social
Senior Lecturer in Algebra and Topology at Cardiff University. All views are my own.
Excited to share details about this upcoming one-day workshop bringing together leading researchers in operator algebras and related fields!
- on Friday, 21st November 2025
- in the Fry Building, School of Mathematics, University of Bristol
For details see: sites.google.com/view/operato...
- on Friday, 21st November 2025
- in the Fry Building, School of Mathematics, University of Bristol
For details see: sites.google.com/view/operato...
LinkedIn
This link will take you to a page that’s not on LinkedIn
lnkd.in
November 11, 2025 at 8:04 PM
Excited to share details about this upcoming one-day workshop bringing together leading researchers in operator algebras and related fields!
- on Friday, 21st November 2025
- in the Fry Building, School of Mathematics, University of Bristol
For details see: sites.google.com/view/operato...
- on Friday, 21st November 2025
- in the Fry Building, School of Mathematics, University of Bristol
For details see: sites.google.com/view/operato...
Reposted by Ulrich Pennig
In case anyone wants to make some of these boards, I put the laser-cutter templates on my blog. divisbyzero.com/2025/11/01/a...
November 1, 2025 at 6:10 PM
In case anyone wants to make some of these boards, I put the laser-cutter templates on my blog. divisbyzero.com/2025/11/01/a...
Reposted by Ulrich Pennig
Full length video here, 9:01 minutes long - amazing work @ledbydonkeys.org.
Trump & Epstein on Windsor castle #fyp
TikTok video by Led By Donkeys
www.tiktok.com
September 17, 2025 at 8:25 AM
Full length video here, 9:01 minutes long - amazing work @ledbydonkeys.org.
'Meta CEO Mark Zuckerberg has told analysts that people without smart glasses may one day be at a "significant cognitive disadvantage" compared to those who do use the tech'
September 16, 2025 at 9:23 AM
'Meta CEO Mark Zuckerberg has told analysts that people without smart glasses may one day be at a "significant cognitive disadvantage" compared to those who do use the tech'
Today was the final day of the 38th British Topology Meeting. It was fun! Great to see so many young people in the field and hear all the recent developments.
September 11, 2025 at 8:00 PM
Today was the final day of the 38th British Topology Meeting. It was fun! Great to see so many young people in the field and hear all the recent developments.
Ladies and Gentlemen! Elle Cordova: www.youtube.com/shorts/AYm9w...
For our scientists
YouTube video by Elle Cordova
www.youtube.com
September 9, 2025 at 10:09 PM
Ladies and Gentlemen! Elle Cordova: www.youtube.com/shorts/AYm9w...
Reposted by Ulrich Pennig
Here is Erisa today at the Gorom refugee settlement. Please share the fundraiser so I can send him more support (in addition to what I have sent personally)
www.gofundme.com/f/aid-for-er...
www.gofundme.com/f/aid-for-er...
September 8, 2025 at 11:09 AM
Here is Erisa today at the Gorom refugee settlement. Please share the fundraiser so I can send him more support (in addition to what I have sent personally)
www.gofundme.com/f/aid-for-er...
www.gofundme.com/f/aid-for-er...
The first step in a project that is dear to my heart has now appeared on the arXiv (arxiv.org/abs/2509.04134). In it we develop a unified framework describing how different notions of symmetries of operator algebras are interlinked. We reveal interesting connections with homotopy theory as well.
G-kernels and Crossed Modules
We develop a unified framework based on topological crossed modules for various lifting obstructions for $Γ$-kernels. It allows us to identify actions, cocycle actions and $Γ$-kernels up to their natu...
arxiv.org
September 5, 2025 at 8:43 AM
The first step in a project that is dear to my heart has now appeared on the arXiv (arxiv.org/abs/2509.04134). In it we develop a unified framework describing how different notions of symmetries of operator algebras are interlinked. We reveal interesting connections with homotopy theory as well.
Reposted by Ulrich Pennig
Just a member of the UK parliament asking me, my family, my neighbours, my colleagues, school teachers, friends and a large proportion of the NHS to leave the country.
And the richest person in the world endorsing the message.
And the richest person in the world endorsing the message.
September 3, 2025 at 4:38 PM
Just a member of the UK parliament asking me, my family, my neighbours, my colleagues, school teachers, friends and a large proportion of the NHS to leave the country.
And the richest person in the world endorsing the message.
And the richest person in the world endorsing the message.
Reposted by Ulrich Pennig
I've a feeling Mr Farage might very much be regretting his trip... round about ...
Now 👇
Now 👇
Rep. Jamie Raskin tears into Nigel Farage as a "far-right pro-Putin politician" and a "Donald Trump sycophant and wannabe".
September 3, 2025 at 3:14 PM
I've a feeling Mr Farage might very much be regretting his trip... round about ...
Now 👇
Now 👇
Reposted by Ulrich Pennig
Okay, big breath...
After more than two years since we published our last documentary on the topic, it's time we returned to Disco Elysium:
www.youtube.com/watch?v=lZEA...
After more than two years since we published our last documentary on the topic, it's time we returned to Disco Elysium:
www.youtube.com/watch?v=lZEA...
We Need to Talk about Disco Elysium, Again
YouTube video by People Make Games
www.youtube.com
August 15, 2025 at 1:23 PM
Okay, big breath...
After more than two years since we published our last documentary on the topic, it's time we returned to Disco Elysium:
www.youtube.com/watch?v=lZEA...
After more than two years since we published our last documentary on the topic, it's time we returned to Disco Elysium:
www.youtube.com/watch?v=lZEA...
Reposted by Ulrich Pennig
Reposted by Ulrich Pennig
We're delighted to be once again co-hosting the Black Heroes of Mathematics Conference, taking place at @DeMorganHouse (and online) on 1 and 2 October.
Register now ➡️ www.lms.ac.uk/events/black...
Register now ➡️ www.lms.ac.uk/events/black...
August 28, 2025 at 6:45 PM
We're delighted to be once again co-hosting the Black Heroes of Mathematics Conference, taking place at @DeMorganHouse (and online) on 1 and 2 October.
Register now ➡️ www.lms.ac.uk/events/black...
Register now ➡️ www.lms.ac.uk/events/black...
Reposted by Ulrich Pennig
We are advertising a Level D/E position in Pure Maths at University of Adelaide (for non-Oz-initiated: E=full Prof, D=one step down).
https://careers.adelaide.edu.au/cw/en/job/517088/associate-professor-professor-de-pure-mathematics
https://careers.adelaide.edu.au/cw/en/job/517088/associate-professor-professor-de-pure-mathematics
August 22, 2025 at 9:15 AM
We are advertising a Level D/E position in Pure Maths at University of Adelaide (for non-Oz-initiated: E=full Prof, D=one step down).
https://careers.adelaide.edu.au/cw/en/job/517088/associate-professor-professor-de-pure-mathematics
https://careers.adelaide.edu.au/cw/en/job/517088/associate-professor-professor-de-pure-mathematics
Reposted by Ulrich Pennig
Alvaro Torras Casas (Cardiff) speaking on "Dataset comparison using persistent homology morphisms" at our #MachineLearning #Math seminar back in May 2023. #MathSky
Alvaro Torras Casas (Cardiff)
Alvaro Torras Casas (Cardiff)31 May 2023"Dataset comparison using persistent homology morphisms"Persistent homology summarizes geometrical information of dat...
www.youtube.com
August 21, 2025 at 8:24 AM
Alvaro Torras Casas (Cardiff) speaking on "Dataset comparison using persistent homology morphisms" at our #MachineLearning #Math seminar back in May 2023. #MathSky
Reposted by Ulrich Pennig
This November the place to be is Brisbane! Registration is now open for QTMC here queertransmath.com - be sure to sign up and tell your friends!
July 20, 2025 at 7:31 PM
This November the place to be is Brisbane! Registration is now open for QTMC here queertransmath.com - be sure to sign up and tell your friends!
Reposted by Ulrich Pennig
Today is my birthday! Could you, please, share my art, it is the best gift an artist can get 💖
August 15, 2025 at 12:38 PM
Today is my birthday! Could you, please, share my art, it is the best gift an artist can get 💖
Reposted by Ulrich Pennig
Reposted by Ulrich Pennig
Are we still having the ICM in Philly next year?
This would more or less halt the ability of scientists and academics from visiting the US to give talks, attend meetings and workshops, collaborate with peers on research and I think that is the primary point. 🧪
The State Department is proposing requiring applicants for business and tourist visas to post a bond of up to $15,000 to enter the United States, a move that may make the process unaffordable for many.
August 5, 2025 at 3:38 AM
Are we still having the ICM in Philly next year?
Quick reminder that registrations for the 38th British Topology Meeting in Cardiff are still open! #topology #MathSky #AcademicSky
Cardiff is hosting the 38th British Topology Meeting from 9th - 11th September 2025. The registration is now open! Come along if you are looking for some interesting talks about all things topological. Details can be found here: sites.google.com/view/btm38 #MathSky #topology #AcademicSky
38th BTM
The meeting will begin on Tuesday 9th September at 13:00 and will close around noon on Thursday 11th September. All talks will be held in Abacws.
sites.google.com
July 25, 2025 at 9:51 AM
Quick reminder that registrations for the 38th British Topology Meeting in Cardiff are still open! #topology #MathSky #AcademicSky
Reposted by Ulrich Pennig
The devastating funding cuts to mathematics research in the US will cut-short the careers of a generation of mathematicians. It really is disgraceful, and unbelievably shortsighted. #MathSky
www.scientificamerican.com/article/can-...
www.scientificamerican.com/article/can-...
Math Is Quietly in Crisis over NSF Funding Cuts
A 72 percent reduction in federal funding is devastating to math research. The American Mathematical Society is offering $1 million in backstop grants—but it’s likely not enough
www.scientificamerican.com
July 25, 2025 at 7:20 AM
The devastating funding cuts to mathematics research in the US will cut-short the careers of a generation of mathematicians. It really is disgraceful, and unbelievably shortsighted. #MathSky
www.scientificamerican.com/article/can-...
www.scientificamerican.com/article/can-...
Reposted by Ulrich Pennig
At last. This really is excellent news! Something the EU had asked for a very long time ago. Looks like Yvette Cooper now lost that battle to limit it to 12 months.
Good. It's high time young Brits and Europeans can get to know each other again.
Good. It's high time young Brits and Europeans can get to know each other again.
Young Europeans may be allowed to stay in UK for longer than a year
A minister has opened the door for a reciprocal youth mobility scheme that could add to net migration figures despite concerns from the Home Office
www.thetimes.com
July 20, 2025 at 8:11 PM
At last. This really is excellent news! Something the EU had asked for a very long time ago. Looks like Yvette Cooper now lost that battle to limit it to 12 months.
Good. It's high time young Brits and Europeans can get to know each other again.
Good. It's high time young Brits and Europeans can get to know each other again.
Reposted by Ulrich Pennig
TalkTV spreads hate and transphobia as if there was no consequences.
Let's prove them wrong.
Join over 10,000 people - send your complaint to Ofcom 👇
action.goodlawproject.org/ofcom-stop-t...
Let's prove them wrong.
Join over 10,000 people - send your complaint to Ofcom 👇
action.goodlawproject.org/ofcom-stop-t...
Ofcom: stop TalkTV broadcasting hate
TalkTV is Rupert Murdoch’s Fox News for the UK – a constant source of toxic hate and far-right lies. Over the last 11 weeks, TalkTV has been spouting transphobic hate again and again – totally ignorin...
action.goodlawproject.org
July 19, 2025 at 6:05 PM
TalkTV spreads hate and transphobia as if there was no consequences.
Let's prove them wrong.
Join over 10,000 people - send your complaint to Ofcom 👇
action.goodlawproject.org/ofcom-stop-t...
Let's prove them wrong.
Join over 10,000 people - send your complaint to Ofcom 👇
action.goodlawproject.org/ofcom-stop-t...
I am visiting Belfast for a conference on topological groupoids and C*-algebras (www.newton.ac.uk/event/tgaw02/). Belfast is pretty in the summer!
July 15, 2025 at 7:06 PM
I am visiting Belfast for a conference on topological groupoids and C*-algebras (www.newton.ac.uk/event/tgaw02/). Belfast is pretty in the summer!