Reductification of parahoric group schemes

This paper demonstrates that any parahoric group scheme over a henselian discretely valued field becomes reductive after a finite Galois extension, allowing it to be recovered as the smoothening of Galois invariants of a reductive model, a result that extends prior work to the wildly ramified case and confirms the Grothendieck–Serre conjecture for generically trivial parahoric torsors in sufficiently good residue characteristics.

Arnab Kundu2026-03-09🔢 math

A Survey on Stacked Intelligent Metasurfaces: Fundamentals, Recent Advances, and Challenges

This survey provides a comprehensive overview of stacked intelligent metasurfaces (SIMs), detailing their physical principles, modeling frameworks, and hardware realizations while examining their role in enabling advanced 6G functionalities like wave-domain signal processing, integrated sensing, and cell-free networks, alongside identifying key challenges for future research.

Chandan Kumar Sheemar, Wali Ullah Khan, Sourabh Solanki, George C. Alexandropoulos, Symeon Chatzinotas2026-03-09🔢 math

Algebraic Invariants of Edge Ideals Under Suspension

This paper investigates how algebraic invariants of edge ideals change under selective graph suspensions, demonstrating that while suspensions over minimal vertex covers consistently preserve regularity and increase projective dimension by one, suspensions over maximal independent sets exhibit uniform behavior only for paths and cycles, with a specific extremal family of paths showing increases in both regularity and the a\mathfrak{a}-invariant.

Selvi Kara, Dalena Vien2026-03-09🔢 math

Graph labellings and external difference families

This paper establishes a systematic framework for constructing digraph-defined external difference families by combining graph blow-up techniques with generalized vertex labellings, resulting in new combinatorial families—including the first infinite construction for specific 2-circular external difference families—and novel results on graph labellings such as α\alpha-valuations for sun graphs.

Gavin Angus, Sophie Huczynska, Struan McCartney2026-03-09🔢 math