Tootfinder

Crossing the phantom divide in scalar-tensor and vector-tensor theories
Shinji Tsujikawa
https://arxiv.org/abs/2508.17231 https://arxiv.org/pdf/2508.17231

Crossing the phantom divide in scalar-tensor and vector-tensor theories
DESI observations of baryon acoustic oscillations (BAOs), combined with cosmic microwave background (CMB) and type-Ia supernova (SN Ia) data, suggest that the dark energy equation of state $w_{\rm DE}$ crosses the phantom divide from $w_{\rm DE} < -1$ to $w_{\rm DE} > -1$ at low redshifts. In shift-symmetric Horndeski and generalized Proca theories with luminal gravitational-wave speed and no direct couplings to dark matter, we show that such a phantom-divide crossing is generically difficult w…

In Hungary, the government has passed legislation limiting the rights of LGBTQ people and dual nationals.
The Hungarian news site Telex reports that the Fidesz majority in the National Assembly approved the 15th amendment to the Constitution by 140 votes to 21. 
Nepszava, a leading social-democratic daily in Hungary, headlines with comments from the Hungarian Helsinki Committee.
The human rights organisation says the amendment aims to "sow fear and divide society&quot…

Press Review - 'Sow fear and divide society': Papers react to Hungary's anti-LGBTQ amendment
PRESS REVIEW – Tuesday, April 15: The press are marking the two-year anniversary of the deadly civil war in Sudan. Also, papers in Hungary react to an amendment limiting the rights of LGBTQ people and dual nationals. Next, two teenagers are arrested in Kenya for attempting to smuggle 5,000 ants out of the country. Finally, Catalan architect Gaudi gets holy recognition on his path to becoming a saint.

Dimension of the isometry group in type N vacuum solutions: an IDEAL approach
Juan Antonio S\'aez, Salvador Mengual, Joan Josep Ferrando
https://arxiv.org/abs/2506.20427

Dimension of the isometry group in type N vacuum solutions: an IDEAL approach
The necessary and sufficient conditions for a type N vacuum solution (with cosmological constant) to admit a group of isometries of dimension $r$ are given in terms of the invariant concomitants of the Weyl tensor. This study requires defining several invariant classes, and for each class, the conditions that determine the dimension are given. Thus, an IDEAL (Intrinsic, Deductive, Explicit and ALgorithmic) characterisation of these spacetimes follows. Some examples show that our algorithmic res…

Inverse Hamiltonian reduction for affine W-algebras in type A
Dylan Butson, Sujay Nair
https://arxiv.org/abs/2508.18248 https://arxiv.org/pdf/2508.18248

Inverse Hamiltonian reduction for affine W-algebras in type A
We give a geometric proof of inverse Hamiltonian reduction for all affine W-algebras in type A at generic level, a certain embedding of the affine W-algebra corresponding to an arbitrary nilpotent in $\mathfrak{gl}_N$ into that corresponding to a larger nilpotent with respect to the closure order on orbits, tensored with an auxiliary algebra of free fields. We proceed by constructing strict chiral quantizations of equivariant Slodowy slices, sheaves of $\hbar$-adic vertex algebras on the arc sp…

De senaste två åren ungefär så har det varit en hel del debatt kring talangutveckling här i Sverige och det här och några efterföljande avsnitt kommer vi att gå igenom några av de mer kontroversiella delarna kring det här. https://tyngre.se/podcast/tyngre…

Talangutveckling del 1 - potential, nivåindelning och selektering | Podcast
Hur hittar vi framtidens stjärnor – och riskerar vi att sålla bort dem för tidigt? I första delen av en serie om talangutveckling diskuterar Jacob och Wille sel

Esbjerg Street Food - jeg takker for anbefalingen, for hele familien er virkelig godt tilfreds!

Lepton flavor violating top quark FCNC at the $\mu$TRISTAN
Abhik Sarkar
https://arxiv.org/abs/2506.18015 https://arxiv.org/pdf/2506.1…

Lepton flavor violating top quark FCNC at the $μ$TRISTAN
We investigate charged lepton flavor violating top quark flavor-changing neutral current interactions at the proposed asymmetric muon-electron collision stage of the $μ$TRISTAN collider, operating at a center-of-mass energy of 346 GeV. Specifically, we study the process $μ^{+} e^{-} \rightarrow t q$ ($t \overline{q} + \overline{t}q$) with $q = u, c$, within the framework of three classes of four-fermion contact interactions: scalar, vector, and tensor operators. A cut-based analysis is perfor…

A look at embedded and immersion chip-cooling tech; industry sources indicate Nvidia is mulling 6,000W to 9,000W TDP for its next-gen GPUs, up from ~1,200W now (Anton Shilov/Tom's Hardware)
https://www.

Orthogonal splitting of the Riemann curvature tensor and its implications in modeling compact stellar structures
A. Rehman, Tayyab Naseer, Nazek Alessa, Abdel-Haleem Abdel-Aty
https://arxiv.org/abs/2506.16725

Orthogonal splitting of the Riemann curvature tensor and its implications in modeling compact stellar structures
Although the interpretation of complexity in extended theories of gravity is available in the literature, its illustration in $f(R,L_{m},\mathcal{T})$ theory is still ambiguous. The orthogonal decomposition of the Riemann tensor results in the emergence of complexity factor as recently proposed by Herrera [1]. We initiate the analysis by contemplating the interior spacetime as a static spherical anisotropic composition under the presence of charge. The modified field equations are derived along…

Multi-field TDiff theories: the mixed regime case
Antonio L. Maroto, Prado Mart\'in-Moruno, Diego Tessainer
https://arxiv.org/abs/2507.16616 https://…

Multi-field TDiff theories: the mixed regime case
We study theories breaking diffeomorphism (Diff) invariance down to the subgroup of transverse diffeomorphisms (TDiff), consisting of multiple scalar fields in a cosmological background. In particular, we focus on models involving a field dominated by its kinetic term and a field dominated by its potential, coupled to gravity through power-law functions of the metric determinant. The Diff symmetry breaking results in the individual energy-momentum tensors not being conserved, although the total…