Tootfinder

Fundamental limits of distributed covariance matrix estimation via a conditional strong data processing inequality
Mohammad Reza Rahmani, Mohammad Hossein Yassaee, Mohammad Reza Aref
https://arxiv.org/abs/2507.16953

Fundamental limits of distributed covariance matrix estimation via a conditional strong data processing inequality
Estimating high-dimensional covariance matrices is a key task across many fields. This paper explores the theoretical limits of distributed covariance estimation in a feature-split setting, where communication between agents is constrained. Specifically, we study a scenario in which multiple agents each observe different components of i.i.d. samples drawn from a sub-Gaussian random vector. A central server seeks to estimate the complete covariance matrix using a limited number of bits communica…

On the Power of Spatial Locality on Online Routing Problems
Swapnil Guragain, Gokarna Sharma
https://arxiv.org/abs/2506.17517 https://

On the Power of Spatial Locality on Online Routing Problems
We consider the online versions of two fundamental routing problems, traveling salesman (TSP) and dial-a-ride (DARP), which have a variety of relevant applications in logistics and robotics. The online versions of these problems concern with efficiently serving a sequence of requests presented in a real-time on-line fashion located at points of a metric space by servers (salesmen/vehicles/robots). In this paper, motivated from real-world applications, such as Uber/Lyft rides, where some limited…

Why we need a standardized state of health definition for electric vehicle battery packs -- a proposal for energy- and capacity-based metrics
Philip Bilfinger, Markus Schreiber, Philipp Rosner, Kareem Abo Gamra, Jan Sch\"oberl, Cristina Grosu, Markus Lienkamp
https://arxiv.org/abs/2508.15517

Why we need a standardized state of health definition for electric vehicle battery packs -- a proposal for energy- and capacity-based metrics
Range and performance are key customer-relevant properties of electric vehicles. Both degrade over time due to battery aging, thus impacting business decisions throughout a vehicle's lifecycle, such as efficient utilization and asset valuation. For practical assessment, aging is often simplified into a single figure of merit - the state of health - typically defined by the battery pack's remaining capacity or energy. However, no standardized method for measuring the state of health at the vehic…

"... abolishing Ofwat and replacing it with a shinier regulator won’t stop sewage dumping or profiteering if the finance and ownership structures stay the same."
Surfers Against Sewage.
Water companies to be overseen by new watchdog to 'prevent abuses of the past', government says - live updates - BBC News
https://www.…

Scrap Ofwat, says major report, as author warns water bills will rise by 30% in five years - live updates
Sir Jon Cunliffe's report into the water sector in England and Wales makes 88 recommendations - including making water meters mandatory.

From Chiral Topological Dynamics to Chiral Topological Amplification: Real vs Imaginary Parameters in a Hermitian Bosonic Chain
Kiran Babasaheb Estake, T. R. Vishnu, Dibyendu Roy
https://arxiv.org/abs/2508.14560

From Chiral Topological Dynamics to Chiral Topological Amplification: Real vs Imaginary Parameters in a Hermitian Bosonic Chain
We propose a Hermitian quadratic bosonic model (QBH) whose dynamical matrix exhibits distinct topological and dynamical phenomena depending on whether the hopping and pairing amplitudes are real or purely imaginary. In the real-parameter regime, the dynamical matrix is unitarily equivalent to four decoupled copies of the sublattice-symmetric non-Hermitian Su-Schrieffer-Heeger (nSSH2) model, thereby inheriting its topological phases and energy spectrum-including the Möbius phase, a gapless topo…

Multi-Source Peak Age of Information Optimization in Mobile Edge Computing Systems
Jianhang Zhu, Jie Gong
https://arxiv.org/abs/2508.14328 https://arxiv.or…

Multi-Source Peak Age of Information Optimization in Mobile Edge Computing Systems
Age of Information (AoI) is emerging as a novel metric for measuring information freshness in real-time monitoring systems. For computation-intensive status data, the information is not revealed until being processed. We consider a status update problem in a multi-source single-server system where the sources are scheduled to generate and transmit status data which are received and processed at the edge server. Generate-at-will sources with both random transmission time and process time are con…

Causality Matters: How Temporal Information Emerges in Video Language Models
Yumeng Shi, Quanyu Long, Yin Wu, Wenya Wang
https://arxiv.org/abs/2508.11576 https://

Causality Matters: How Temporal Information Emerges in Video Language Models
Video language models (VideoLMs) have made significant progress in multimodal understanding. However, temporal understanding, which involves identifying event order, duration, and relationships across time, still remains a core challenge. Prior works emphasize positional encodings (PEs) as a key mechanism for encoding temporal structure. Surprisingly, we find that removing or modifying PEs in video inputs yields minimal degradation in the performance of temporal understanding. In contrast, reve…

Superdielectrics: Disorder-induced perfect screening in insulators
Ilia Komissarov, Tobias Holder, Raquel Queiroz
https://arxiv.org/abs/2508.14962 https://…

Superdielectrics: Disorder-induced perfect screening in insulators
We study the relationship between the quantities that encode the insulating properties of matter: the ground-state quantum metric, the average localization length, and the electric susceptibility. By examining the one-dimensional Anderson insulator model and the Su-Schrieffer-Heeger chain with chiral disorder, we demonstrate that the former two measures are proportional in one-dimensional systems near criticality, and both are determined by the properties of the hybridized localized states arou…

Since I have my own matrix server that we use for all close family chats, with all the bridges I barely use official clients like Signal and stuff. Feel so free and independent.
Now also pretty. What an amazing android client!
https://fluffychat.im/

Weighted $k$-Server Admits an Exponentially Competitive Algorithm
Adithya Bijoy, Ankit Mondal, Ashish Chiplunkar
https://arxiv.org/abs/2507.12130 https://

Weighted $k$-Server Admits an Exponentially Competitive Algorithm
The weighted $k$-server is a variant of the $k$-server problem, where the cost of moving a server is the server's weight times the distance through which it moves. The problem is famous for its intriguing properties and for evading standard techniques for designing and analyzing online algorithms. Even on uniform metric spaces with sufficiently many points, the deterministic competitive ratio of weighted $k$-server is known to increase doubly exponentially with respect to $k$, while the behavio…