Tootfinder

🇺🇦 #NowPlaying on KEXP's #MiddayShow
Car Seat Headrest:
🎵 The Catastrophe (Good Luck with That, Man)
#CarSeatHeadrest
https://carseatheadrest.bandcamp.com/track/the-catastrophe-good-luck-with-that-man
https://open.spotify.com/track/0yXlQbT5xqQDP2wij6XQpy

This https://arxiv.org/abs/2411.00957 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Modularity of $d$-elliptic loci with level structure
We consider the generating series of special cycles on $\mathcal{A}_1(N)\times \mathcal{A}_g(N)$, with full level $N$ structure, valued in the cohomology of degree $2g$. The modularity theorem of Kudla-Millson for locally symmetric spaces implies that these series are modular. When $N=1$, the images of these loci in $\mathcal{A}_g$ are the $d$-elliptic Noether-Lefschetz loci, which are conjectured to be modular. In the appendix, it is shown that the resulting modular forms are nonzero for $g=2$…

Ukraine nimmt zwei Chinesen wegen Spionageverdacht fest
Der ukrainische Inlandsgeheimdienst SBU hat nach eigenen Angaben zwei chinesische Staatsbürger festgenommen, die verdächtigt werden, Daten über die Produktion ukrainischer Neptun-Raketen gesammelt zu haben.
Der SBU erklärt, er habe einen 24-jährigen ehemaligen Studenten in Kiew festgenommen, nachdem ihm der Dienst Dokumente übergeben hatte. Später wurde auch sein Vater …
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Ukraine-Liveblog: ++ Russland greift mit Raketen und Drohnen an ++
Russland hat laut der ukrainischen Luftwaffe in der Nacht mit mehr als 700 Drohnen und mehreren Raketen angegriffen. US-Präsident Trump erwägt laut Medienberichten, Kiew ein Flugabwehrsystem zu liefern.

Metsäjätit myyvät, luonto maksaa hinnan! Vaadi muutosta metsäyhtiöiden toimintaan! #luonto …

Metsäyhtiöt vastuuseen! Suomen luonto ei ole kertakäyttötuote - Greenpeace Suomi
Luontokato kiihtyy, hiilinielut romahtavat, mutta metsäyhtiöt jatkavat samaan malliin. Jotain rajaa! Allekirjoita vetoomus.

Optimisation of Electrolyser Operation: Integrating External Heat
Matthias Derez, Alexander Hoogsteyn, Erik Delarue
https://arxiv.org/abs/2507.06796 https:…

Optimisation of Electrolyser Operation: Integrating External Heat
Integrating external heat into electrolysers can reduce the electrical power demand for carbon-neutral hydrogen production. Efficient operation requires detailed models that incorporate heat availability and its effect on startup costs. This paper advances existing operational models by endogenously modelling startup costs and direct heat integration, based on a piecewise linear approximation of the electrochemical equations. We analyse the impact of low- and high-temperature heat integration o…

Bounding destruction timescales of minor planets orbiting white dwarfs with the sesquinary catastrophe
Dimitri Veras, Matija \'Cuk
https://arxiv.org/abs/2507.05090

Bounding destruction timescales of minor planets orbiting white dwarfs with the sesquinary catastrophe
Dynamical activity attributed to the destruction of minor planets orbiting white dwarfs has now been photometrically monitored in individual systems for up to one decade, long enough to measure significant cessation and re-emergence of transit features. Further, periodicities which hint at the presence of debris orbiting exterior to the white dwarf Roche radius, along with widely varying estimates for debris disc lifetimes (up to Myrs), complicate theories for the formation and dynamical evolut…

This https://arxiv.org/abs/2408.06616 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Gromov-Witten invariants in family and quantum cohomology
A moduli space of stable maps to the fibers of a fiber bundle is constructed. The new moduli space is a family version of the classical moduli space of stable maps to a non-singular complex projective variety. The virtual cycle for this moduli space is also constructed, and an analogue of Gromov-Witten invariants is defined. As an application, we recover the formula for the number of rational degree d curves in P3, whose image lies in a plane in P3 (known as planar curves in P3), intersecting r…

Quantum jet Hopf algebroids by cotwist
Xiao Han, Shahn Majid
https://arxiv.org/abs/2507.02848 https://arxiv.org/pdf/2507.02848…

Quantum jet Hopf algebroids by cotwist
We introduce a cotwist construction for Hopf algebroids that also entails cotwisting or `quantisation' of the base and which is dual to a previous twisting construction of Xu. Whereas the latter applied the construction to the algebra of differential operators on a classical base $B$, we show that the dual of this is the algebra of sections $J^\infty(B)$ of the jet bundle and hence the latter forms a Hopf algebroid, which we identify as a quotient of the pair Hopf algebroid $B\otimes B$. This c…

Quasinormal modes of Floquet media slabs
Benjamin Vial, Richard V. Craster
https://arxiv.org/abs/2507.02784 https://arxiv.org/pdf/250…

Quasinormal modes of Floquet media slabs
Exploiting non-Hermitian wave-matter interactions in time-modulated media to enable the dynamic control of electromagnetic waves requires advanced theoretical tools. In this article we bridge concepts from photonic quasinormal modes (QNMs) and time-varying metamaterials providing the foundation for designing dynamic optical devices with prescribed scattering properties. Establishing the QNM framework for slabs with time-periodic permittivity, and solving the associated nonlinear eigenvalue prob…

Representations of finite subgroups of Cremona groups
Alexander Duncan, Bailey Heath, Christian Urech
https://arxiv.org/abs/2507.04474 https://

Representations of finite subgroups of Cremona groups
The Cremona group of rank n over a field k is the group of birational automorphisms of the n-dimensional projective space over the field k. We study the minimal dimension such that all finite subgroups of the Cremona group have a faithful representation of that dimension over the same field. We find the exact value for rank 1 and 2 over all fields. We prove that the value is infinite for all fields of positive characteristic and rank greater than one. For many fields of characteristic 0, which …