Tootfinder

While I'm definitely against AI art, I can appreciate the difficulties of the directors here. Perhaps they could have recreated it with diaspora actors or something, but I do recognize that it gets tricky.
https://www.the-independent.com/arts-enter…

Lights, camera, algorithm: First fully AI-generated film set to premiere at Tribeca Festival
Iranian director Ash Koosha said, ‘I would have preferred to make this film with a crew, with actors, with the dignity of a full production’

No matter what you look for, the algorithm offers up Coldplay.

Funny story, that Claude thing. But I hate when I read that „AI goes rogue“. A „misdemeanor“. Or it „apologized“ and „admitted“.
It’s a fricking text extruder that does random things because the algorithm thinks those words fit into its context. If you let such a program execute whatever command it spits out - that’s on you. If the cloud provider keeps backups on the same drive as the original data, that’s on them and you should try suing them.

Replaced article(s) found for cs.CR. https://arxiv.org/list/cs.CR/new
[1/1]:
- Double Index Calculus Algorithm: Faster Solving Discrete Logarithm Problem in Finite Prime Field
Wen Huang
…

#AI's #Affordability Crisis
https://blog.dshr.org/2026/06/ais-affordability-crisis.ht…

Instagram expands Your Algorithm to its main feed, letting users choose topics they want to see, and is working to support requests for people, moods, and more (Jay Peters/The Verge)
https://www.theverge.com/tech/947898/meta-instagram-your-algorithm-main-fee…

You can just tell the Instagram algorithm what you want now
Instagram is going to let you tweak what its algorithm shows you on your main feed.

After weeks of searching, I think I have broken @… ->
I am looking for a fast cheapish route home from UK. Eurostar extmely expensive, so I thought, how about ferry from Harwich to Hoek and then train to Copenhagen. Railfinder routes me back from Hoek van Holland to Harwich and home via Eurostar... 😂
Same algorithm, same...

“headingoffset is Not the Document Outline Algorithm”
https://adrianroselli.com/2026/06/headingoffset-is-not-the-document-outline-algorithm.html
Hi, just me heading off some bad advice I’m starting to see in developer venues.

heading‍offset is Not the Document Outline Algorithm
Hi, just me heading off some bad advice I’m starting to see in developer venues. Background The proposed Document Outline Algorithm, where headings would automatically reset themselves to the appropriate level based on their position in the DOM structure, was never part of a final HTML specification. It was quickly…

I was a guest on the Heavy Networking podcast, talking about routing performance and the recent improvements to the shortest path algorithm. A fun discussion for me at least https://packetpushers.net/podcasts/hea

Hearst, Dow Jones, Condé Nast and NJ.com are setting subscription renewal prices using dynamic pricing, often using AI and referred to as "personalized offers" (Hanaa' Tameez/Nieman Lab)
https://www.niemanlab.org/2026/…

Hate “The Algorithm?” RSS Is One of the Tools You’ve Been Looking For
RSS is one of the best examples we have of the open web, where we can design and customize how we experience the internet, not the other way around.
https://www.eff.org/deeplinks/2026/06/hate

Hate “The Algorithm?” RSS Is One of the Tools You’ve Been Looking For
Since at least the moment Facebook introduced (and apologized for) its News Feed, “the algorithm” has been shorthand for the ways the tech giants control what we see and when we see it. In the age of enshittification, there is a push to reclaim our feeds and networks. Good news: there’s a tool that’s been around for decades that can help wrangle many of your feeds into something manageable: Really Simple Syndication, more commonly known as RSS.

Endlose Selbstüberschätzung …
Jeff Bezos Is Funding a Wild Hunt for the Brain's 'Core Algorithm' - Slashdot https://science.slashdot.org/story/26/06/08/0418226/jeff-bezos-is-funding-a-wild-hunt-for-the-brains-cor…

#ReleaseDay The new version of https://thi.ng/geom-sdf is automatically preprocessing the vertices given for 2D polygons & polylines to remove any coincident and colinear ones (using Douglas-Peucker algorithm). Thi…

2D Signed Distance Field creation from @thi.ng/geom shapes, conversions, sampling, combinators

I now use ads on short form video feeds as a "stopping point" indicator.
Any time I want to be done with the endless scroll, I wait for an ad. Then I close the app.
I know someone is getting metrics on this somewhere. Maybe, it'll net me less ads in my algorithm. And it weirdly has helped me break the scrolling cycle, too.

from my link log —
The APLR(1) algorithm for compact LR(1) parsers is simpler and more capable than IELR(1).
https://branchtaken.com/reports/aplr1/aplr1
saved 2026-06-13

How does searching for new information often look?
Evgeniya Sukhodolskaya is joining #bbuzz26 to introduce a new instrument for search pipeline builders: propagating query-results relevance right inside the search algorithm of a search engine.
Learn more here : https://2026.berlinbuzzwords.de/session/relevance-feedback-inside-the-search-engine/

Nikita Bier says X made a "tweak to boost visibility of your posts to your mutuals", or those who users follow back, to avoid replies becoming a "battleground" (Lucas Ropek/TechCrunch)
https://techcrunch.com/2026/07/13/x-ju

X just tweaked its algorithm to make it more friendly, less battleground | TechCrunch
The social media site says it will amplify posts made by users' mutual followers' to give the feed more of a communal feel.

seriously who wrote the pathfinding algorithm for cats

Hot take: DKIM signatures with ed25519 are largely useless🔥🔑
I know what you're thinking. RSA is bad. You read that blogpost with the "f" word. (It's not good.) This isn't about ed25519 vs. RSA, but about how DKIM works
Here's the problem: if you introduce a new crypto algorithm into a protocol, you need to know if the other side" supports it. But in DKIM, you don't. You're sending e-mails to arbitrary receivers. DKIM has no mechanism to tel…

"It places page cache pages in a writable scatterlist, separated from the legitimate write region by nothing more than an offset boundary. The design assumes every AEAD algorithm will confine its writes to the intended destination, but nothing in the API enforces this, and nothing documents it as a requirement.
Unfortunately, one AEAD algorithm breaks this silent invariant."
"No other standard AEAD algorithm in the kernel [uses memory that doesn't belong to it as a scratch pad]. GCM, CCM, and regular authenc all confine their writes to the legitimate output area. authencesn alone writes past the boundary."
I'm actually amazed that there's only one bug here. Somehow almost everyone just managed to do the right thing, despite no mechanism enforcing it and no documentation describing it. That's just amazing. It's a testament to the skill of those developers, despite an incredibly bad design.
#copyfail

It's funny to go through Facebook after something like a football game. Because their algorithm is so stupid, it shows me tons of posts from before the game, with all the hope, cheering etc., and one feels like a time traveler, wanting to say "you'll see, you'll see"...
Not here in Mastodon :)
Nothing to be ashamed of in yesterday's game, Croatia showed up good, and congratulations to England.
Although the first goal was stolen.

I’d like to understand Apple Music’s algorithm for “music just for you”. It is consistently good! It doesn’t over index stuff that I might temporarily get into, but builds it in more if I listen for longer. And almost every song it picks is great!

#JulieNolke: You love your #algorithm
https://www.youtube.com/watch?v=zQ4_Otz9gXk 😉

Generation of synthetic CT images from optical scanning for superficial mold brachytherapy
Scott B. Crowe (Royal Brisbane and Women's Hospital, Brisbane Qld, Australia, Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane Qld, Australia, University of Queensland, Brisbane Qld, Australia, Queensland University of Technology, Brisbane Qld, Australia), Emily Simpson-Page (Royal Brisbane and Women's Hospital, Brisbane Qld, Australia), Jenna Luscombe (Royal Brisbane and Women's Hospital, Brisbane Qld, Australia), Rachael Wilks (Royal Brisbane and Women's Hospital, Brisbane Qld, Australia, Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane Qld, Australia, University of Queensland, Brisbane Qld, Australia), Tanya Kairn (Royal Brisbane and Women's Hospital, Brisbane Qld, Australia, Herston Biofabrication Institute, Metro North Hospital and Health Service, Brisbane Qld, Australia, University of Queensland, Brisbane Qld, Australia, Queensland University of Technology, Brisbane Qld, Australia)
https://arxiv.org/abs/2606.25221 https://arxiv.org/pdf/2606.25221 https://arxiv.org/html/2606.25221
arXiv:2606.25221v1 Announce Type: new
Abstract: Optical 3D scanning systems allow the acquisition of accurate models of patient anatomy, suitable for use in the design of simple 3D-printable patient-matched medical devices with 3D modelling software. This study developed and demonstrated the use of superficial brachytherapy surface mold design workflow that utilizes data from optical 3D surface scanning and enables a commercial brachytherapy treatment planning system to be used for catheter positioning and dose optimization steps. Synthetic CT images were generated from 14 optically scanned anatomical models of human participants. Models and skin textures ac-quired from the optical scans were imported into Autodesk Meshmixer, where the treatment area was delineated, and treatment and device volumes produced. 3D Slicer was used to convert the body, treatment and device volumes to DICOM CT and RTSTRUCT data. The synthetic CT data and contoured volumes were imported into Varian Eclipse, where catheters were designed, and dwell positions and times optimised for dose coverage of the treatment volume. The lack of in-ternal anatomy did not compromise dose calculations, due to clinical use of a TG43 based algorithm. Once 3D printed, molds can be imaged in-situ during CT simulation, and reconstructed, for clinical dose calculation and plan approval.
toXiv_bot_toot

#bwa upgrade: Fast genomic read alignment with minibwa
https://arxiv.org/abs/2606.15357
"It produces equivalent or slightly improved small variant calls, and more importantly, enables long-read alignmen…

Fast genomic read alignment with minibwa
Motivation: BWA-MEM remains a popular short-read mapper especially for the purpose of variant calling. Several groups have accelerated this algorithm as it has been the performance bottleneck of many current workflows. However, constrained by the original design, these drop-in replacements could only achieve limited speedup. Breaking changes to BWA-MEM are required for further improvement. Results: We developed minibwa for aligning short and accurate long reads against a reference genome. It …

from my link log —
Learning a regular language by inferring a DFA with the TTT algorithm.
https://rahul.gopinath.org/post/2026/06/09/ttt-grammar-inference/
saved 2026-06-11

Using the standard decimal long multiplication algorithm but discarding all carried digits, compute 23³.

Your mom is not using a post-quantum key exchange algorithm!

Impressive work on #cycling network development by @… at @… building the data and algorithm foundation for active mobility planning and resea…

"Seven weeks on X's For You feed shifted political views 4.7 percentage points towards the Republican party"
For those of you still there, your presence on #Twitter isn't helping.
https://www.nature.co…

The political effects of X’s feed algorithm - Nature
Among users initially on a chronological feed, 7 weeks of exposure to X’s algorithmic feed in 2023 shifted political attitudes and account-following behaviour in a more conservative direction compared with those remaining on a chronological feed, whereas switching the feed setting in the opposite direction, from algorithmic to chronological, had no effect.

Also, unlike this one, many of my skeets don’t get here. Something about @… doesn’t pick them all up. Probably bsky is sinking the stuff they determine not interesting or whatever.
I despise algorithmic feeds where I can’t fix my algorithm. @…

Bill Cole (@scconsult.com)
Repeating what's in my profile… I treat Bluesky as a 2nd platform & mostly am on the #Fediverse. My bridged Mastodon account got "suspended" by Bluesky for no reason I could discern, so my posts there never get here. & while I often retoot my skeets, I don't turn many of my toots into skeets.

Could the solution to toxic, addictive #socialMedia be as simple as this: make social media liable for recommendation algorithm outputs?
Section 230 and similar law insulate companies from what their users post. But a decision to put something in front of a user that the user hasn't explicitly asked for is fundamentally a speech act *by the company*, for which it can be liable.

The Algorithm found this interesting news video for me about e-motorbikes in Kenya, and e-stuff in Africa in general. https://www.youtube.com/watch?v=OBoNsdPIt9Q
They didn't mention it, but in the video you can see that they have a battery charge/change service for e-motos. This is one c…

X really twisted us to think that followers and engagement mean something. More people look at posts without interacting on these new social media platforms. We aren’t chasing an algorithm for engagement. Don’t give up.

@tomscott.name: 'The old system produced too few entrances. The new one produces too few exits from itself. It helps us find our people, but it also folds that discovery back into the machinery of feeds, metrics, recommendations and monetisation.
...
The internet satisfies the need before it becomes a movement.'

Lucky Strike Entertainment,
formerly known as Bowlero Corporation,
the private equity–backed behemoth that in the past 10 years has bought more than 350 of the nation’s bowling alleys
and transformed them into a
(to quote the Bowlero website)
“quirky, edgy, retro-inspired bowling phenomenon”
that has deprioritized league bowling,
escalated the cost of bowling with algorithm-driven dynamic pricing,
and accelerated the demise of one of the 20th …

How private equity destroyed an American pastime
A class-action suit against Lucky Strike Entertainment is a sad coda to the end of bowling.

Improved Approximation Guarantees for Groupwise Maximin Share Fairness
Georgios Amanatidis, Anna Korfiati, Evangelos Markakis, Christodoulos Santorinaios
https://arxiv.org/abs/2606.04731 https://arxiv.org/pdf/2606.04731 https://arxiv.org/html/2606.04731
arXiv:2606.04731v1 Announce Type: new
Abstract: We study the problem of fairly allocating a set of indivisible goods to a set of $n$ agents with additive valuation functions. We focus on the very demanding notion of \textit{groupwise maximin share fairness} (GMMS), which requires that each agent $i$ receives value comparable to their maximin share, where the latter is computed \textit{with respect to any subset of agents that contains $i$}. We show that it is possible to compute $(\phi-1)$-approximate GMMS allocations in polynomial time, where $\phi \approx 1.618$ is the golden ratio). This improves on the previously known guarantee of $4/7$ of Chaudhury et al. [SICOMP; 2021] and Amanatidis et al. [TCS; 2020]. We propose a simple algorithm that maintains the same main properties as the Draft-and-Eliminate algorithm of Amanatidis et al. [TCS, 2020] and we improve on the approximation guarantee analysis by carefully bounding the relevant value within any subinstance induced by the restriction of our allocation to a subset of agents. Our analysis is asymptotically tight for algorithms that share these properties and has the additional benefit of giving improved guarantees for restricted settings; in particular, when the agents agree on the top $n$ goods or when the number of agents is small. To illustrate the challenges of going beyond the guarantees of our algorithm, we also present a variant with an improved approximation of $(\sqrt{10}-1)/3 \approx 0.72$ for the case of three agents. To achieve this improvement we partially characterize the maximin share guarantees of short picking sequences for a small number of goods.
toXiv_bot_toot

TOPLAP is the *Temporary* Organisation for Live Algorithm Programming, but is 22 years old and still going. I think it was actually disbanded at some point over 10 years ago but it carried on by mistake. The problem with vaguely anti-hierarchical and distributed organisations is that they're quite difficult to disband.

"I never expected to find my news […] on a federated social network that half the internet has never heard of. […] But there's something quietly beautiful about a place where people just... share what they know.
No brand deals, no engagement metrics, no algorithm nudging you toward rage. Just someone who spent twenty years studying Arctic policy posting a thread at 2 AM because they think you should understand what's happening.
It's the internet I was promised in…

Call for Proposals: Art, Aura, and the Algorithm
https://ift.tt/oeWF2EI
updated: Friday, May 15, 2026 - 11:49amfull name / name of organization: Pacific Northwest College…
via Input 4 RELCFP

Partitioned Iterative Quantum Scheduling of Satellites for Urgent Disaster Response: Case study of Wildfire
Lucas T. Braydwood, Taejin Park, Hirofumi Hashimoto, Zoe Gonzalez Izquierdo, Andrew Michaelis, Eleanor Rieffel, Shon Grabbe
https://arxiv.org/abs/2606.12310 https://arxiv.org/pdf/2606.12310 https://arxiv.org/html/2606.12310
arXiv:2606.12310v1 Announce Type: new
Abstract: The standard in Earth-observation tasks today is having near real-time access to surface images in response to changing conditions. For instance, as urban environments interface more with wildlands and wildfires become less predictable, their tracking with satellite resources becomes essential. This requires the coordination of increasingly large constellations of satellites, giving rise to challenging computational problems. With wildfire detection and tracking as a backdrop, we investigate the power of special purpose and novel computing paradigms to tackle the ensuing satellite scheduling problems, making a compelling case for quantum algorithms. We bring quantum scheduling algorithms closer to implementation by examining both the emerging iterative quantum algorithm framework, which comes with analytic guarantees compared to some classical algorithms, and distributed quantum computing methods whose relevance is on the rise as utility-scale problems begin to get solved with quantum computers. Drawing strength from several computing fronts, we develop a distributed/parallelization scheme in conjunction with the quantum algorithm design and apply these techniques to real-world datasets for wildfire detection. While our quantum subprocesses are currently too small to see significant quantum advantage, our results validate the utility of these techniques, and continue forging the path toward distributed quantum computing.
toXiv_bot_toot

(LinkedIn) The channel count arms race https://www.linkedin.com/posts/timir-datta-6b67886_the-channel-count-arms-race-neural-interfaces-share-7480637564358598657-zQbl/

The channel count arms race. Neural interfaces keep chasing higher channel counts, on the assumption that more channels mean more useful information. The truth is more nuanced: the returns are often… | Timir Datta
The channel count arms race. Neural interfaces keep chasing higher channel counts, on the assumption that more channels mean more useful information. The truth is more nuanced: the returns are often diminishing and application-dependent, while the costs to the system and to the tissue keep rising. 1. Every channel carries a systems cost. Each channel needs access to an analog front end, and every acquired channel burns power before any algorithm sees the signal. The AFE can consume a signifi…

from my link log —
Modelling BBR's interactions with traditional TCP loss-based congestion control.
https://blog.apnic.net/2020/01/24/modelling-bbrs-interactions-with-loss-based-congestion-control/
saved 2020-01-25 …

Modelling BBR’s interactions with loss-based congestion control | APNIC Blog
Guest Post: While BBR is supposed to be a rate-based algorithm, when competing with other flows, BBR is window-limited.

Segment-Wise Soft Robotics Inspired Flexible Antenna Arrays: Design and Optimization
Shuaishuai Han, Konstantinos Ntougias, Elio Faddoul, Ioannis Krikidis
https://arxiv.org/abs/2606.11771 https://arxiv.org/pdf/2606.11771 https://arxiv.org/html/2606.11771
arXiv:2606.11771v1 Announce Type: new
Abstract: In this paper, we propose a segment-wise soft robotic antenna (SRA) system, where each soft robotic arm referred to as a tentacle, comprises multiple independently controllable segments with bending, elongation-retraction, and sweeping motions. By adjusting segment motion parameters, the positions of surface-mounted antennas are reconfigured, distinguishing it from conventional reconfigurable antenna (RA) systems. Based on this model, we propose two antenna deployment schemes: the segmented end-antenna configuration (SEAC), where fixed antennas are mounted at the segment ends and reconfigured via segment motions; and the hybrid end-and-intermediate antenna configuration (HEIAC), where RAs are further integrated as intra-segment antennas. In HEIAC, soft-robot segment deformation provides large-scale spatial reconfiguration, while RAs enable fine-grained adjustment. For SEAC, we formulate a sum-rate maximization problem accounting for inter-segment connectivity and the nonlinear mapping from segment deformation parameters to antenna coordinates, and develop a penalty dual decomposition-projected gradient ascent (PDD-PGA) algorithm. For HEIAC, we jointly optimize segment deformation, intra-segment antenna positions, and antenna activation using a block coordinate descent (BCD)-PDD-PGA algorithm with greedy backward antenna selection. Simulation results demonstrate that the proposed schemes substantially outperform fixed-position antenna arrays and conventional RA baselines. In particular, SEAC and HEIAC achieve 37.9% and 32.1% sum-rate gains over conventional 3D reconfigurable arrays, respectively, while SEAC provides up to a 49.3% gain in compact array deployments.
toXiv_bot_toot

Flourish, which is building Cortex AI, a brain-like synthetic intelligence system that uses less power than LLMs, raised $500M, including $100M from Jeff Bezos (Steven Levy/Wired)
https://www.wired.com/story/jeff-bezos-is-funding-a-wild-hunt-for-t…

Jeff Bezos Is Funding a Wild Hunt for the Brain’s ‘Core Algorithm’
With $500 million in funding and a reported $2.5 billion valuation, Flourish wants to reinvent AI by putting real neurons under the microscope.

Just wrote a fun little algorithm for iterating through all grid positions within X euclidean distance from a center, roughly in order of distance but also mostly ensuring each position yielded is at least diagonally adjacent to the previous. It's a fun problem to think about with lots of design tradeoffs and many valid solutions.
My solution requires that the origin be on the grid (I think?) and uses a bunch of caching instead of a bajillion distance checks, although I don't actually know what the memory/speed tradeoff is like or whether there are any gains at all (could be net losses, which I'm starting to wonder about more as I write this post). Thankfully I don't expect performance to be very critical here anyways, and doing the caching actually helped separate some logic in a useful way.
A fun little diversion from bigger stuff in the project and a reminder of some of the joys of programming design at a small scope. Feels kinda like mastering the local town's minigame while you're stuck on the main quest in an RPG.
#programming

Catch 22
The marketing podcast for anyone who's over the copy-paste AI slop information filling their algorithm...
Great Australian Pods Podcast Directory: https://www.greataustralianpods.com/catch-22/

When there's a new version out, I usually try out Mastodon's new features; but also existing ones to see if there's improvements.
For a long time now, Mastodon's "suggested accounts" algorithm shows accounts that haven't posted in years—I think that's maybe a low-hanging fruit to fix for onboarding.
/cc @…

TL;DR - Anyone know an iOS SSH client that supports post-quantum cryptography key exchange algorithms ?
I am not an iOS (or macOS) user, but I recently tweaked a server's sshd setup to no longer offer `curve25519-sha256` as a key exchange algorithm.
The only report I've had from users of this being problematic for them is one iOS user. They've tried both "Prompt version 2.6.19 build 401391" and "ShellBean Version 3.1.11 (326)" and they fail to conn…

Hahahahahahahahahahhahhahhahahhahhahhahahha
*choking sounds*
Hahahhahahahahahahahahahahahahahaah
https://bsky.app/profile/koldinium.com/post/3mky4hw5a5c2i

This #Veritasium video is a damned good intro on routing algorithms starting with Dijkstra’s seminal shortest path algorithm. The visuals are impressive and they make extensive use of #OpenStreetMap data.

RE: https://mefi.social/@MissConstrue/116501419475132635
"[T]here's something quietly beautiful about a place where people just... share what they know. No brand deals, no engagement metrics, no algorithm nudging you toward rage. Just someone who…

During the vacation, I noticed that I'm so glad I never went into the algorithm-based-influencer-business.
Every hike wuold have come with a "I *have* to create some footage for video" plus scheduling videos & photos to provide new media regularly ...
It would just have literally killed the experience of several hikes.

On the Performance and Implementation of Parallax free Video See-Through Displays
Ricardo Augusto Borsoi, Guilherme Holsbach Costa
https://arxiv.org/abs/2607.16484 https://arxiv.org/pdf/2607.16484 https://arxiv.org/html/2607.16484
arXiv:2607.16484v1 Announce Type: new
Abstract: In see-through systems an observer watches a (background) scene partially occluded by a display. In this display, usually positioned close to the observer, a region of the background scene is shown, yielding the sensation that the display is transparent. To achieve the transparency effect, it is very important to compensate the parallax error and other distortions caused by the image acquisition system. In this paper a detailed study of a video see-through methodology with parallax correction is performed. In a system composed by two cameras -- one directed to the user and another to the background scene -- and a display, the relative position between the user, the display and the scene is estimated using a feature detection algorithm and the parallax error is compensated assuming a planar scene model. The application of the proposed methodology on Driver Assistance Systems (DAS) is proposed. A theoretical assessment of the algorithm shows that although approximations are proposed to simplify the methodology and reduce the computational cost, such as the planar scene model and fixed working distance, on some practical situations their effects can be neglected without noticeable impact on the perceptual quality of the solution.
toXiv_bot_toot

A study of websites created since 2022 found 1 in 3 are AI-generated text. And their characteristics follow my prediction that AI will act as compression algorithm on cultural heritage.
https://www.linkedin.com/posts/jonippolito…

RE: https://mastodon.social/@transactualuk/116970223959736793
I think this is quite common. People, or especially teams, thinking that their Mastodon/Fedi account isn't getting traction, because it ain't tracked. You don't see the numbers.
Number of people who are being spied upon reading your posts: Zero, because there ain't no spying-upon here.
Only when you say "Goodbye" do you hear from the people who will miss you.
The answer is to press the like button more. It ain't feeding an algorithm but it is letting people know they are being heard and understood.

Replaced article(s) found for stat.AP. https://arxiv.org/list/stat.AP/new
[2/2]:
- changepointGA: An R package for Fast Changepoint Detection via Genetic Algorithm
Mo Li, QiQi Lu

A formal log(Re)-cost framework for the engineering turbulence problem
Jiaqi Li, Robert F. Kunz, George Huang, Xiang I. A. Yang
https://arxiv.org/abs/2607.20199 https://arxiv.org/pdf/2607.20199 https://arxiv.org/html/2607.20199
arXiv:2607.20199v1 Announce Type: new
Abstract: In fluid engineering, the turbulence problem is the longstanding challenge of obtaining accurate predictions of engineering quantities at affordable computational cost. Viewed through computational complexity, a practical algorithm requires cost growth no worse than $O(N)$, where $N$ denotes problem size. For turbulent flows, the problem size may be approximated by the number of dynamically relevant scales and hence by the Reynolds number $Re$. We propose a multi-fidelity, physics-constrained, data-driven framework designed to meet this criterion under stated assumptions. We augment the Spalart--Allmaras model through field inversion and machine learning using a constrained formulation that preserves the law of the wall. The model is trained at a low Reynolds number, where high-fidelity data are affordable, and deployed at higher Reynolds numbers. For a mean-flow-aligned grid in a wall-bounded flow, fixed spanwise resolution, and steady-solver cost linear in grid-point count, the low-fidelity RANS prediction scales as $O(\log(Re))$. The high-fidelity calculation and learning stage each contribute $O(Re^0)$ relative to the target Reynolds number, giving an overall formal cost of $O(\log(Re))$. In plane channel flow, a model trained at $Re_\tau=1000$ corrects the wake-layer error of the baseline model and retains the improvement at $Re_\tau=5200$. In the periodic hill, a model trained at $Re_b=5600$ is tested at $Re_b=10595$, $19000$, and $37000$. The constrained formulation preserves separation and recovery behavior as Reynolds number increases, yields the lowest root-mean-square error across all tests, and exhibits nearly Reynolds-number-independent error, indicating robust extrapolation.
toXiv_bot_toot

from my link log —
Faster zlib/DEFLATE decompression on arm64 and x86.
https://dougallj.wordpress.com/2022/08/20/faster-zlib-deflate-decompression-on-the-apple-m1-and-x86/
saved 2022-08-20

Faster zlib/DEFLATE decompression on the Apple M1 (and x86)
DEFLATE is a relatively slow compression algorithm from 1991, which (along with its wrapper format, zlib) is incredibly widely used, for example in the PNG, Zip and Gzip file formats and the HTTP, …

An interview with creator Amelia Dimoldenberg on retaining rights to her show Chicken Shop Date, staying on YouTube, new ventures, including a TV show, and more (Katie Drummond/Wired)
https://www.wired.com/story/the-big-interview-podcast-amelia-dimoldenberg/…

The Secret to Amelia Dimoldenberg’s Online Superstardom? Control
The host of “Chicken Shop Date” joined WIRED’s “Big Interview” podcast to talk about turning down bad deals, beating the algorithm, and the importance of being over-prepared.

Just occurred to me that I have never had the experience of perceiving an algorithm in what YouTube wants to show me. Others mention it often. I guess I would need to watch more than one video in a visit and stop tossing their cookies.

Crosslisted article(s) found for stat.ME. https://arxiv.org/list/stat.ME/new
[1/2]:
- Optimizing Irreversible Perturbations of the Unadjusted Langevin Algorithm
Qianyu Julie Zhu, Youssef Marzouk, Konstantinos Spiliopoulos, Benjamin Zhang

Replaced article(s) found for cs.PF. https://arxiv.org/list/cs.PF/new
[1/1]:
- The World's Fastest Matching Engine Algorithm
Jake Yoon
https://arxiv.org/abs/2606.01183 https://mastoxiv.page/@arXiv_csDC_bot/116679523715331912
toXiv_bot_toot

Build-Authorized Evidence for Opaque Calls: A Fail-Closed Rewrite-Authority Boundary
Zhonghua Yi (Toka Language Research Group)
https://arxiv.org/abs/2607.18949 https://arxiv.org/pdf/2607.18949 https://arxiv.org/html/2607.18949
arXiv:2607.18949v1 Announce Type: new
Abstract: Detached semantic facts about opaque native providers do not by themselves justify compiler rewrites: rewrite authority must be confined to the accepted fact, selected provider and build, caller, callback environment, observation, and runtime target. We present a build-authorized path-effect interface that enforces this boundary through fail-closed authorization and link receipts. The design separates receipt closure, callback-environment closure, and projection identity, and passes accepted facts to LLVM through a narrow internal API. We use one-hop topology-load reuse as a minimal observable witness of authority, not as the optimization target.
A conservative LLVM consumer reuses a pointer observation only from a noalias root or one constant nonzero projection. Rocq models prove conditional refinement and authority non-amplification under explicit effect, alias, compiler/ABI, and target-resolution premises. We instantiate checked production with Toka: a source-summary gate emits exact LLVM IR, a separate IR checker accepts only a bounded topology-preserving subset, and only accepted IR is compiled into the receipt-bound provider object. A bounded static Darwin/arm64 profile also checks the final direct branch target.
Across issuer-declared readv, recvmsg, and Cairo boundaries, authorized IR retains each opaque call, reduces the relevant loads from two to one, and preserves observed results; mismatched providers, builds, callbacks, projections, and unsupported IR remain neutral. A libjpeg case is rejected because its callback environment is open, while a bound callback singleton demonstrates the supported closure rule. The contribution is a checked deployment-compiler boundary with an explicit trust and applicability frontier, not a uniquely expressive effect encoding or a new load-elimination algorithm.
toXiv_bot_toot

Constant Approximation for Hylland--Zeckhauser Equilibria
Yonglei Yan, Zhengyang Liu
https://arxiv.org/abs/2606.06317 https://arxiv.org/pdf/2606.06317 https://arxiv.org/html/2606.06317
arXiv:2606.06317v1 Announce Type: new
Abstract: We present a polynomial-time algorithm for computing a $1/e$-approximate Hylland--Zeckhauser (HZ) equilibrium. This establishes the \emph{first} efficient approximation guarantee for HZ equilibria in settings with multi-valued utilities. Our main technical contribution is a novel utility stratification technique that reduces the original multi-valued market to a structured bi-valued instance. This reduction allows us to efficiently compute the approximation by leveraging the exact algorithm of Vazirani and Yannakakis.
toXiv_bot_toot

Perceptions of visual-to-auditory sensory substitution (VASS) technology among students with visual impairments and special educators https://journals.sagepub.com/doi/10.1177/02646196261450976 "applies The vOICe algorithm to convert visual images into auditory input&quot…

i’m amused by this story of the less-random-than-expected mullvad vpn exit addresses because it’s an unexpected consequence of lemire’s nearly-divisionless bounded random number algorithm https://lobste.rs/c/tvuhtr

Mullvad exit IPs as a fingerprinting vector
1 comment

A medical student reverse-engineered AI tools used by medical colleges on suspicion they were filtering his applications, highlighting AI-driven hiring concerns (Todd Feathers/Wired)
https://www.wired.com/story/he-couldnt-land-a-job-interview-was-ai-to-blame/

He Couldn’t Land a Job Interview. Was AI to Blame?
Armed with some Python and a white-hot sense of injustice, one medical student spent six months trying to figure out whether an algorithm trashed his job application.

Verification and Performance Assessment of NuDEAL, a GPU-Accelerated Deterministic Transport Framework on Unstructured Meshes
Kyung Min Kim, Jaeuk Im, Han Gyu Lee, Yeon Sang Jung
https://arxiv.org/abs/2607.01591 https://arxiv.org/pdf/2607.01591 https://arxiv.org/html/2607.01591
arXiv:2607.01591v1 Announce Type: new
Abstract: High-fidelity neutronic analyses of advanced reactors require deterministic transport solvers capable of handling complex unstructured geometries while maintaining computational efficiency. This work presents the development and verification of three GPU-accelerated deterministic solvers implemented within a unified framework, Neutronics using Deterministic Finite Element Algorithm (NuDEAL): the planar Method of Characteristics coupled with the Hybrid Finite Element Method (MOC/HFEM), the Discontinuous Galerkin Method of Characteristics (DGMOC), and the Discontinuous Finite Element discrete ordinate method (DFEM-SN). These solvers provide complementary capabilities for consistently solving the multigroup transport equation and can be selectively employed to balance accuracy, computational cost, and memory requirements for a given problem. All methods emphasize efficient GPU execution by leveraging memory alignment, compressed-flux storage, and sequential azimuthal sweeps. The solvers are validated on the C5G7 benchmark and applied to advanced reactor problems, including the ABTR, Empire microreactor, and MSRE. DFEM-SN achieved the highest accuracy, with eigenvalue errors below 50 pcm, while MOC/HFEM and DGMOC provided superior efficiency, with single-GPU runtimes comparable to those of large CPU clusters. The results demonstrate that deterministic GPU solvers on unstructured meshes can deliver both accuracy and scalability, enabling practical whole-core simulations for heterogeneous advanced reactors. The unified NuDEAL framework establishes a foundation for future extensions toward transient and multiphysics analyses on large-scale GPU architectures.
toXiv_bot_toot

Koopman-Operator Spectral Decomposition for Nonlinear Motion Suppression in Dynamic Contrast-Enhanced MRI of the Head and Neck
Renjie He
https://arxiv.org/abs/2607.19401 https://arxiv.org/pdf/2607.19401 https://arxiv.org/html/2607.19401
arXiv:2607.19401v1 Announce Type: new
Abstract: We build a motion suppression pipeline based on Koopman operator theory, which provides a way to turn nonlinear dynamics into linear ones by looking at the data through the right set of mathematical "lenses" (called observables). We test three versions of this idea: plain DMD that works directly on pixel values, an extended version (EDMD) that adds physically motivated features like squared intensities and spatial gradients to better capture how the MRI signal and tissue motion interact, and a neural network version that tries to learn the best features automatically. A key practical contribution is time-course repetition: we tile the entire temporal series multiple times before decomposition, which does not change the underlying dynamics but gives the algorithm more data to work with, fixing a dimensionality bottleneck that otherwise prevents the extra features from helping. The full pipeline works slice by slice, dividing each image into small overlapping blocks, applying the Koopman lifting and DMD to separate slow contrast enhancement from fast motion based on their characteristic frequencies, and blending the corrected blocks back together.
toXiv_bot_toot

Split Radiance Cascades: Real-Time Global Illumination via Sparse Radiance Probes
Rouli Freeman, Alexander Sannikov
https://arxiv.org/abs/2607.20384 https://arxiv.org/pdf/2607.20384 https://arxiv.org/html/2607.20384
arXiv:2607.20384v1 Announce Type: new
Abstract: Radiance probe methods are a popular and well-tested approach for approximating diffuse global illumination for real-time graphics, but they commonly suffer from a lack of detail due to the large spacing between probes. Radiance Cascade (RC) fixes this by increasing spatial resolution and reducing angular resolution for light and occlusion from closer objects, which allows it to provide details at all scales without noise or aliasing. However, leading implementations of RC either run in 2D or screenspace, due to the prohibitive costs of storing high-detail volumetric radiance information.
In this work, we adapt Radiance Cascades for accurate real-time 3D diffuse global illumination using a sparse hashmap to store world-space probes. We introduce ray splitting, a method for calculating radiance intervals used in RC by tracing rays from visible surfaces and calculating their contribution to cascades based on their hit distance. We evaluate our algorithm, Split Radiance Cascades, on a variety of scenes, and demonstrate that it can provide high-quality indirect illumination in both single-frame and temporally accumulated contexts.
toXiv_bot_toot

An iterative Ising decoder for quantum error correction codes
Yuanqi Liu, Weilei Zeng, Peixiang Li, Yantong Liu, Guangyao Huang, Yingwen Liu, Dongyang Wang, Junjie Wu, Lingling Lao
https://arxiv.org/abs/2606.12301 https://arxiv.org/pdf/2606.12301 https://arxiv.org/html/2606.12301
arXiv:2606.12301v1 Announce Type: new
Abstract: The Ising framework maps the decoding problem in quantum error correction onto ground-state optimization of a classical Hamiltonian, in which $X$-$Z$ error correlations enter as cross terms. Under phenomenological depolarizing noise, the exact joint formulation contains up to 8-body interactions for the toric code and 10-body for the $6.6.6$ color code. These high-order terms degrade solver convergence, inflate runtime, and raise the auxiliary spin overhead when embedding into native 2-body Ising hardware. In this work, we propose the iterative low-order decoding (ILOD) algorithm, which alternates between $X$- and $Z$-type sub-Hamiltonians, approximating cross-type correlations through Bayesian priors that reweight each type's couplings using the other type's inferred error configuration. This halves the maximum body count of interaction terms in the Hamiltonian, accelerating the solver, restoring convergence at larger code distances, and reducing the total spin count for 2-body embedding by a factor of $2.5$. For the toric code, ILOD attains a threshold of $4.73%$ versus $4.83%$ for the joint formulation, with the empirical runtime ratio scaling as $(0.81)^d$. For the $6.6.6$ color code, their thresholds agree within statistical uncertainty for small code distances, and ILOD remains convergent for larger distances where the joint formulation fails to converge despite a larger annealing budget.
toXiv_bot_toot

I am trying to restrain my boosting habits more. I realized that duplicate boosts are still a nuisance for some folks, so I am trying to remember that most toots I see because of boosting have probably hit the feeds of everyone who follows me.
I still have old #FowlSite algorithm-feeding habits, even when that's not really a thing here.

Replaced article(s) found for cs.PF. https://arxiv.org/list/cs.PF/new
[1/1]:
- Redundant Array Computation Elimination
Zixuan Wang, Liang Yuan, Xianmeng Jiang, Kun Li, Junmin Xiao, Yunquan Zhang
https://arxiv.org/abs/2506.21960 https://mastoxiv.page/@arXiv_csPF_bot/114771182875836481
- \texttt{Range-Arithmetic}: Verifiable Deep Learning Inference on an Untrusted Party
Ali Rahimi, Babak H. Khalaj, Mohammad Ali Maddah-Ali
https://arxiv.org/abs/2505.17623 https://mastoxiv.page/@arXiv_csCR_bot/114572910759753105
- Compiler-First State Space Duality and Portable $O(1)$ Autoregressive Caching for Inference
Cosmo Santoni, Anmol Thapar
https://arxiv.org/abs/2603.09555 https://mastoxiv.page/@arXiv_csLG_bot/116210185886117277
- The World's Fastest Matching Engine Algorithm
Jake Yoon
https://arxiv.org/abs/2606.01183 https://mastoxiv.page/@arXiv_csDC_bot/116679523715331912
toXiv_bot_toot

from my link log —
Mechanized type inference for record concatenation as in Nix.
https://haskellforall.com/2026/07/mechanized-type-inference-for-record-concatenation
saved 2026-07-07

Mechanized type inference for record concatenation
Type inference algorithm for biased record concatenation

Fast Wave-optics Rendering of Multiplane Images for 3D Holographic Displays
Brian Chao, Dario Seyb, Nathan Matsuda, Oliver Cossairt, Yang Zhou, Douglas Lanman, Gordon Wetzstein, Grace Kuo, Changwon Jang
https://arxiv.org/abs/2607.19731 https://arxiv.org/pdf/2607.19731 https://arxiv.org/html/2607.19731
arXiv:2607.19731v1 Announce Type: new
Abstract: Recent advances in neural rendering have unlocked unprecedented capabilities in 3D reconstruction and novel view synthesis, giving rise to applications such as virtual fly-throughs of a 3D scene reconstructed from a set of sparse, casually captured images. However, these renderings are viewed on a computer screen or conventional VR headsets as 2D images, greatly limiting the perceptual realism and immersiveness of such experiences. The rapid development in novel 3D scene representations calls for dedicated rendering algorithms that convert these readily-available 3D contents into formats that are compatible with emerging 3D display technologies, such as holographic displays. In this paper, we propose a wave-optics rendering pipeline that works with multiplane images (MPIs) for efficient and high-quality hologram synthesis. Our MPI-based computer-generated holography algorithm greatly outperforms state-of-the-art primitive-based CGH algorithms in terms of runtime, achieving speedups up to 250,000x while achieving comparable image quality, and significantly outperforms conventional layer-based CGH algorithms in terms of image quality. We validate our method extensively on a wide variety of 3D scene datasets both in simulation and through experimentally captured results, showing exceptional 3D focal stack and 4D light field reconstruction performance without sacrificing efficiency.
toXiv_bot_toot

Replaced article(s) found for cs.GT. https://arxiv.org/list/cs.GT/new
[1/1]:
- Best-of-Both-Worlds Fairness of the Envy-Cycle-Elimination Algorithm
Jugal Garg, Eklavya Sharma
https://arxiv.org/abs/2410.08986 https://mastoxiv.page/@arXiv_csGT_bot/113304502509503455
- Deterministic-Allocation and Anonymous Joint Advertising in E-commerce Platforms
Zhen Zhang, Luowen Liu, Wanzhi Zhang, Zitian Guo, Kun Huang, Qi Qi, Qianlong Xie, Xingxing Wang
https://arxiv.org/abs/2506.02435 https://mastoxiv.page/@arXiv_csGT_bot/114623889823025585
- Chance-Constrained Correlated Equilibria for Robust Noncooperative Coordination
Jaehan Im, Ufuk Topcu, David Fridovich-Keil
https://arxiv.org/abs/2603.14141 https://mastoxiv.page/@arXiv_csGT_bot/116243473506703974
- The Stability of Online Algorithms in Performative Prediction
Gabriele Farina, Juan Carlos Perdomo
https://arxiv.org/abs/2602.24207 https://mastoxiv.page/@arXiv_csLG_bot/116159080059392879
toXiv_bot_toot

Crosslisted article(s) found for physics.comp-ph. https://arxiv.org/list/physics.comp-ph/new
[1/2]:
- Interpolation of Microscale Stress and Strain Fields Based on Mechanical Models
Wenzhe Shan, Udo Nackenhorst
https://arxiv.org/abs/2104.09749
- Joint discovery of governing partial differential equations from multi-source datasets by competi...
Hao Xu, Siyu Lou, Yuntian Chen, Dongxiao Zhang
https://arxiv.org/abs/2606.30699 https://mastoxiv.page/@arXiv_csLG_bot/116843565775934283
- LinApart3: efficient algorithm for multivariate partial fraction decomposition with linear denomi...
L. Fek\'esh\'azy, A. Kardos
https://arxiv.org/abs/2606.30708 https://mastoxiv.page/@arXiv_hepph_bot/116843629511193799
- Introducing AuriGLOBES: the effect of compressive tides, compact object-induced mass loss, and si...
Pablo Contreras Guerra, Robert J. J. Grand, Marta Reina-Campos, Claudio Dalla Vecchia
https://arxiv.org/abs/2606.30746 https://mastoxiv.page/@arXiv_astrophGA_bot/116843732310368458
- Time-dependent adaptive mesh refinement solver for the Gross-Pitaevskii-Poisson equations
Iv\'an \'Alvarez-Rios
https://arxiv.org/abs/2606.30827 https://mastoxiv.page/@arXiv_astrophGA_bot/116843767701812779
- Computed materials proposals depart from the structural memory of experimental discovery
Dan Nguyen, Karen Cao, Brian Chu, Nick Lemoff, Paul Kienzle, William Ratcliff II
https://arxiv.org/abs/2606.30967 https://mastoxiv.page/@arXiv_condmatmtrlsci_bot/116843665854969922
- An Enhanced RPA-LDA Model for Ion Stopping Power from Cold Matter to High-Energy Density Plasmas:...
Thomas A. Mehlhorn, Ming Feng Gu, Igor Golovkin
https://arxiv.org/abs/2606.30978 https://mastoxiv.page/@arXiv_physicsplasmph_bot/116843597824839239
- Full-Wave Green's-Function Modeling of Collective Single-Photon Emission in Non-Markovian Open-Sy...
Hyunwoo Choi, Jisang Seo, Junwoo Gim, Bowoo Jang, Weng C. Chew, Dong-Yeop Na
https://arxiv.org/abs/2606.31317 https://mastoxiv.page/@arXiv_quantph_bot/116843791099390803
- Side-Chain Tuning of Thermal-Expansion Crossover in Metal-Organic Frameworks
Wei Qiu, Penghua Ying
https://arxiv.org/abs/2606.31417 https://mastoxiv.page/@arXiv_condmatmtrlsci_bot/116843748631678308
toXiv_bot_toot

from my link log —
An arbitrary-palette positional dithering algorithm.
https://bisqwit.iki.fi/story/howto/dither/jy/
saved 2026-06-30 https://

Dependencies and Dataflow in Seed-Filter-Extend Pipelines
Shiv Sundram
https://arxiv.org/abs/2606.06811 https://arxiv.org/pdf/2606.06811 https://arxiv.org/html/2606.06811
arXiv:2606.06811v1 Announce Type: new
Abstract: Comparing genomes is critical for discovering mutations, tracking evolutionary lineages, and advancing cross-species genomics. Fundamentally, this reduces to an O(n^2) string-matching dynamic programming (DP) problem, a challenge that has driven decades of performance research. However, executing a strict O(n^2) DP algorithm is computationally intractable for genomes spanning millions to billions of base pairs. Consequently, modern aligners rely on global heuristics to identify thousands of candidate similarity regions between species. Unfortunately, these methods are burdened by complex serial dependencies. Once candidate regions are identified, the pipeline executes localized DP alignments, which introduce their own non-trivial heuristics and irregular data dependencies. While parallelizing dense, two-dimensional DP is a well-studied problem, accelerating this end-to-end pipeline is significantly more challenging. Parallelizing across candidate regions and offloading irregular, heuristic-laden local alignments to modern hardware (such as GPUs) remains a major hurdle. In this work, we address the challenge of overcoming these serial bottlenecks by optimizing the global pipeline across regions. We take inspiration from four papers: LASTZ, SegAlign, Darwin-WGA, and SNAP, synthesizing findings across each to inform optimizations, which we either prototype or implement directly in LASTZ.
toXiv_bot_toot

Replaced article(s) found for cs.GT. https://arxiv.org/list/cs.GT/new
[1/1]:
- Best-of-Both-Worlds Fairness of the Envy-Cycle-Elimination Algorithm
Jugal Garg, Eklavya Sharma

Crosslisted article(s) found for physics.comp-ph. https://arxiv.org/list/physics.comp-ph/new
[1/1]:
- A High-Order Arbitrary Lagrangian-Eulerian Discontinuous Galerkin Method for the Boltzmann Equati...
Atakan Aygun, Onur Ata, Tim Warburton, Ali Karakus
https://arxiv.org/abs/2607.00199 https://mastoxiv.page/@arXiv_physicsfludyn_bot/116849258941218034
- A Multi-Resolution Finite-Volume Inspired Deep Learning Framework for Spatiotemporal Dynamics Pre...
Xin-Yang Liu, Xiantao Fan, Jian-Xun Wang
https://arxiv.org/abs/2607.00460 https://mastoxiv.page/@arXiv_csCE_bot/116849212144848429
- When is vaccine prioritization worth optimizing?
Mi Feng, Zhaohua Lin, Changsong Zhou, Liang Tian
https://arxiv.org/abs/2607.00484 https://mastoxiv.page/@arXiv_physicsbioph_bot/116849279781216938
- A Nonstandard Finite Difference Scheme for a Nonlinear Parabolic Equation with p-Laplacian-Type D...
Achraf Zinihi, Matthias Ehrhardt, Moulay Rchid Sidi Ammi
https://arxiv.org/abs/2607.00489 https://mastoxiv.page/@arXiv_mathNA_bot/116849363932310131
- The BiP-PRISM algorithm for fast and scalable core-loss STEM-EELS simulations
Philipp Pelz
https://arxiv.org/abs/2607.00756 https://mastoxiv.page/@arXiv_condmatmtrlsci_bot/116849366488683473
toXiv_bot_toot

Should Demand Models Incorporate Competitor Prices? Oblivious Learning and Algorithmic Collusion
Yuhang Wu, Assaf Zeevi
https://arxiv.org/abs/2606.05363 https://arxiv.org/pdf/2606.05363 https://arxiv.org/html/2606.05363
arXiv:2606.05363v1 Announce Type: new
Abstract: On a platform with many sellers, should a pricing algorithm explicitly model competitors' prices when learning demand? Classical learning arguments suggest an affirmative answer: ignoring competitors induces model misspecification and inefficiency. In contrast, recent work on algorithmic collusion suggests that strategic obliviousness -- deliberately ignoring competitor prices -- may facilitate collusive outcomes and improve profits. We study this modeling choice in a stylized competitive market with unknown noisy demand, in which multiple sellers repeatedly set prices and estimate demand via iterated least squares, and either incorporate competitors' prices into their demand models (informed) or ignore them (oblivious). We first show that, relative to a monopolist, an oblivious seller in a competitive market must explore more aggressively to compensate for the loss of dynamic competitor information. Building on this insight, we characterize market dynamics when all sellers are oblivious and show that prices converge to the competitive outcome under sufficient exploration, while a continuum of pseudo-equilibria arises when exploration decays. Analyzing the resulting price trajectories, we uncover an excursion phenomenon that gives rise to transient collusive patterns that dissipate as learning progresses. In markets with both oblivious and informed sellers, the informed strictly out-earn the oblivious. Read as a strategy game, the modeling choice has a unique Nash equilibrium: the all-informed market, in which prices converge to the competitive outcome efficiently. Overall, our results indicate that collusive patterns are not robust and are not sustained by oblivious modeling; therefore, incorporating competitor information, together with sufficient price exploration, remains a reliable strategy for sellers in competitive markets.
toXiv_bot_toot

Regret Minimization in Single-Dimensional Contract-Design with Binary Actions
Riccardo Poiani, Martino Bernasconi, Andrea Celli
https://arxiv.org/abs/2606.06125 https://arxiv.org/pdf/2606.06125 https://arxiv.org/html/2606.06125
arXiv:2606.06125v1 Announce Type: new
Abstract: We study principal-agent problems in which a principal commits to an outcome-dependent payment scheme (i.e., a contract) in order to induce an agent to take a costly action leading to a favorable outcome. We consider the online extension of the classical (one-shot) principal-agent problem, in which the principal repeatedly interacts with agents by proposing contracts over multiple rounds. The principal has no information about the agents and, crucially, does not observe their actions. As a result, the principal must learn an optimal contract using only the realized outcomes observed at each round. We focus on the setting with binary actions and single-dimensional agent types, where the agent's private type represents their cost per unit-of-effort. For adversarial-type sequences, we provide tight $\Theta(T^{2/3})$ regret guarantees. Remarkably, this rate is completely independent of the number of outcomes $m$. The upper bound is based on two key components: 1) a reduction to a one-dimensional threshold optimization problem and 2) a non-uniform discretization to handle the non-Lipschitz nature of the problem. Moreover, in the case of a single (fixed) hidden type, we show that it is possible to improve the rates and provide a tight $\widetilde{\Theta}(\sqrt{T})$ regret bound. Our algorithm is based on an explore-then-commit strategy where we first approximately learn the hidden type via a stochastic binary search, and then we commit to a ``robustified'' near-optimal contract.
toXiv_bot_toot

Non-obvious Manipulability in the Additively Separable Group Activity Selection Problem
Maria Fomenko (Gran Sasso Science Institute), Giovanna Varricchio (University of Calabria)
https://arxiv.org/abs/2606.05048 https://arxiv.org/pdf/2606.05048 https://arxiv.org/html/2606.05048
arXiv:2606.05048v1 Announce Type: new
Abstract: In this work, we study the additively separable Group Activity Selection Problem (AS-GASP) in an imperfect information setting, where agents have private preferences over activities and weights over other agents. Our goal is to design mechanisms that assign agents to activities based on their declared preferences and weights, with the objective of maximizing social welfare while ensuring truthful reporting. We, therefore, focus on the notion of non-obvious manipulability (NOM), a form of resilience to manipulation. We first investigate the relationship between NOM and social welfare optimality. In this regard, our main result shows that, when preferences and weights are arbitrary or non-negative, any optimal mechanism is non-obviously manipulable. In contrast, when either preferences or weights are binary, we show that optimality and NOM may be incompatible. We then turn to computational aspects. While it is known that computing an optimal outcome for the AS-GASP is NP-hard even in restricted settings, we establish a strong inapproximability result showing that no polynomial-time algorithm can guarantee a bounded approximation ratio when preferences and weights may take arbitrary values. In turn, when preferences are non-negative, we show that a bounded approximation is possible, and we present two asymptotically optimal approximation mechanisms that are also guaranteed to satisfy NOM.
toXiv_bot_toot

James O'Brien is on the radio asking if the government ought to leave Twitter.
He seems to have finally understood that there is no level playing field there, that the algorithm can't be used for good. That if it started to do good, the owners would just change it.
He left when he understood that the place is overrun with trolls and moderated only to keep the woke in check.
James blocked me ages ago, and I'd not ring in, but the key thing he's missing is this:
Elon musk has his own shitposting troll site that he owns.
Trump has his own shtposting troll site that he owns.
Mark Zuckerberg has his own shitposting troll site that he owns. He's got like four.
The blockchain people have their own shitposting troll site that they own (that's the one O'Brian uses).
If the government wants to use a shitposting troll site, they should also use one that they own.
Likewise LBC radio presenters really. If they want to use a shitposting troll site, they should probably use one that they own and moderate themselves.
And then, consensually, with no obligation, if they want, each of the shitposting troll sites can federate together with the others in a mesh, so that they can talk to each other and the conversation can flow between them but ownership and control is distributed to individual organisations.
Then we could decentralize ownership of the means of communication and avoid this argument about whether the government should be on twitter so we can instead argue whether UK Social should block or federate with Musk's Nazi Troll site or not.
And this system exists of course. LBC could have their own shitposting troll site by the end of next week and moderate it as they see fit.
#fediverse #mastodon #twitter #socialMedia