sigma

SIGMA 60-600mm f/4.5-6.3 DG DN OS Sport lens review

SIGMA 60-600mm f/4.5-6.3 DG DN OS Sport lens review Sigma’s 60-600mm Sport lens is one of the most versatile wildlife lenses around, but can its huge zoom range outweigh the heavy design? The Sigma 60-600mm f/4.5-6.3 DG DN Sport lens boasts one of the most versatile focal ranges on the market and effortlessly produces beautiful wildlife shots. The images are sharp, contrasty and true to life, but for us, the weight is a dealbreaker. - + Image quality is lovely - + Versatile focal length - +...

SIGMA 150-600mm f/5-6.3 DG DN OS Sport lens review

SIGMA 150-600mm f/5-6.3 DG DN OS Sport lens review How does this third-party lens compare to the native Sony equivalent? We tested both to see whether it’s worth going native or whether you should save your money. A very capable option for newer wildlife photographers looking for an affordable super-telephoto lens without sacrificing too much image quality. -

Sigma BF Review (2026): Eccentric but Strangely Lovable

Sigma has a long history of releasing, let's call them, eccentric cameras. Last year, the brand put out the BF, which continues in that tradition. Because it is very different, lacking features like a mechanical shutter, viewfinder, and storage-card slot, among others, I wanted to spend some extra time with it before passing judgment.

Sigma Court Victory Eases Uncertainty Around Lithium Expansion

The Sigma Lithium mine near Itinga, Minas Gerais state, Brazil.

SIGMA: A Versatile Streaming Graph Partitioner for Vertex- and Edge-Balanced Distributed GNN Training

Announce Type: new Abstract: Distributed Graph Neural Network (GNN) training depends critically on how the underlying graph is partitioned across compute resources. Existing graph partitioners focus either on vertex partitioning or edge partitioning and typically optimize only a single communication objective (edge cut or vertex cut) under a single balance constraint (vertex balance or edge balance).

‘Two Sigma’ S&P Rally Signals Easy Money Has Already Been Made

The memory of $\omega$-regular and BC($\Sigma_2^0$) objectives

arXiv:2502.05840v3 Announce Type: replace Abstract: In the context of 2-player zero-sum infinite-duration games played on (potentially infinite) graphs, the memory of an objective is the smallest integer k such that in any game won by Eve, she has a strategy with <= k states of memory. For omega-regular objectives, checking whether the memory equals a given number k was not known to be decidable. In this work, we focus on objectives in BC(Sigma0^2), i.e. recognised by a potentially infinite...

The memory of $\omega$-regular and BC($\Sigma_2^0$) objectives

arXiv:2502.05840v4 Announce Type: replace Abstract: In the context of 2-player zero-sum infinite-duration games played on (potentially infinite) graphs, the memory of an objective is the smallest integer k such that in any game won by Eve, she has a strategy with <= k states of memory. For omega-regular objectives, checking whether the memory equals a given number k was not known to be decidable. In this work, we focus on objectives in BC(Sigma0^2), i.e. recognised by a potentially infinite...

The Privacy Subsidy in Continuous-Time Kyle: Cumulative Welfare under Noise-Perturbed Order-Flow Observation

Announce Type: replace Abstract: We extend the closed-form privacy-subsidy result of Nakamura~(2026, arXiv:2605.15746) from the single-period Kyle model to continuous-time. A committed Bayesian automated market maker observes the aggregate order flow perturbed by an independent Brownian privacy channel of diffusion intensity $\sigma_\varepsilon$. Under the Markovian linear equilibrium, the price-impact coefficient is $\lambda = \sigma_v / \sqrt{\sigma_u^2 + \sigma_\varepsilon^2}$ -- constant...

Irreducibility of Semigroup Morphisms

arXiv:2603.15177v2 Announce Type: replace Abstract: We introduce and study the notion of irreducibility of semigroup morphisms over a finite alphabet. Given an alphabet $\Sigma$, a morphism $\varphi:\Sigma^+\rightarrow\Sigma^+$ is irreducible if any factorisation $\varphi=\psi_2\circ\psi_1$ can only be satisfied if $\psi_1$ or $\psi_2$ is a trivial morphism; otherwise, $\varphi$ is reducible. This definition provides a notion of primality in the endomorphism monoid of the free semigroup -- a...