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Morita equivalence of shifted symplectic Lie n-groupoids
Milena Weiershausen
https://arxiv.org/abs/2505.24018 https://arxiv.org/pdf/2…

Morita equivalence of shifted symplectic Lie n-groupoids
Symplectic structures on higher objects like Lie groupoids have been studied for some time now, but not all of the proposed definitions are preserved under Morita equivalence of Lie groupoids, in turn giving rise to a consistent notion of symplectic stacks. Recently, this concept has been generalized to m-shifted symplectic forms on Lie n-groupoids, which are indeed preserved under Morita equivalence of Lie n-groupoids. In this paper, we give a rigorous proof for this statement.

This https://arxiv.org/abs/2412.06043 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Probing Gravity -- Fundamental Aspects of Metric Theories and their Implications for Tests of General Relativity
Guided by the Einstein equivalence principle that identifies the phenomenon of gravitation as a manifestation of the dynamics of spacetime in contrast to a localizable force, we review and explore its consequences on formulating a theory of gravity. The resulting space of metric theories of gravity may address open conceptual and observational puzzles through a wealth of effects beyond general relativity, whose traces can be searched for within today's and tomorrow's gravitational testing groun…

Ukraine greift offenbar Militärbasis in Ostsibirien an
Die Ukraine hat nach Angaben ihres Inlandsgeheimdienstes SBU einen Angriff auf eine russische Militärbasis in Ostsibirien ausgeführt. Nach dem Angriff auf die rund 4.200 Kilometer von der ukrainischen Grenze entfernt gelegene Luftwaffenbasis Belaja in der Region Irkutsk sei auf dem Stützpunkt ein Feuer ausgebrochen, hieß es aus Geheimdienstkreisen.
Den Angaben zufolge fü…
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Ukraine-Liveblog: ++ Wadephul betont Waffenhilfe ++
Außenminister Wadephul betont, dass Deutschland der Ukraine weitreichende Militärhilfe leisten wird. Nach einem Angriff auf eine ukrainische Ausbildungseinheit mit zwölf Toten tritt der Kommandeur der ukrainischen Armee, Drapatij, zurück.

Dynamical dark energy in the no-scale Brans-Dicke gravity
Muzi Hong, Kyohei Mukaida, Tsutomu T. Yanagida
https://arxiv.org/abs/2506.01543 https://

Dynamical dark energy in the no-scale Brans-Dicke gravity
We add a new scalar field in the no-scale Brans-Dicke gravity and require it to have a global O(2) symmetry with the original scalar field in the Brans-Dicke gravity. This gives us a new massless scalar field in the Einstein frame due to the SO(2) symmetry. We then explicitly break the O(2) symmetry to a $D_4$ symmetry, and this scalar field gains a periodic potential. This scalar field can serve as the quintessence field to explain dark energy. If we further add the $R^2$ term and the non-mini…

Gravitomagnetism from Temporal Dimensional Reduction
Mehran Z-Abyaneh, Mehrdad Farhoudi
https://arxiv.org/abs/2506.00525 https://arxi…

Gravitomagnetism from Temporal Dimensional Reduction
We propose that the Taub-NUT metric can be envisaged as a (3+1) dimensional analog of the Kaluza-Klein (4+1) dimensional metric. After dimensional reduction of the Taub-NUT metric to (3) spatial dimensions, by treating time as the extra curled dimension (since the closed time-like curves can exist in the Taub-NUT framework, such a dimensional reduction is justified), we end up with three dimensional Einstein field equations plus the Maxwell equations for the gravitomagnetic field, which also ac…

Resonant interlayer coupling in NbSe$_2$-graphite epitaxial moir{\'e} superlattices
S. Mo, K. Kovalenka, S. Buchberger, B. K. Saika, A. Azhar, A. Rajan, A. Zivanovic, Y. -C. Yao, R. V. Belosludov, M. D. Watson, M. S. Bahramy, P. D. C. King
https://arxiv.org/abs/2506.00449

Resonant interlayer coupling in NbSe$_2$-graphite epitaxial moir{é} superlattices
Moir{é} heterostructures, created by stacking two-dimensional (2D) materials together with a finite lattice mismatch or rotational twist, represent a new frontier of designer quantum materials. Typically, however, this requires the painstaking manual assembly of heterostructures formed from exfoliated materials. Here, we observe clear spectroscopic signatures of moir{é} lattice formation in epitaxial heterostructures of monolayer (ML) NbSe$_2$ grown on graphite substrates. Our angle-resolved …

Quantum Search for Gravitational Wave of Massive Black Hole Binaries
Fangzhou Guo, Jibo He
https://arxiv.org/abs/2505.24459 https://a…

Quantum Search for Gravitational Wave of Massive Black Hole Binaries
Matched filtering is a common method for detecting gravitational waves. However, the computational costs of searching large template banks limit the efficiency of classical algorithms when searching for massive black hole binary (MBHB) systems. In this work, a quantum matched filtering algorithm based on Grover's algorithm is applied to the MBHB signals. It is demonstrated that the quantum approach can reduce the computational complexity from $O(N)$ to $O(\sqrt{N})$ theoretically, where $N$ is …

This https://arxiv.org/abs/2501.08161 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Cosmological model with Gong-Zong Parametrization in $f(R,L_m)$ gravity
We present the cosmic expansion scenarios in the $f(R, L_m)$ gravity studied by using the dark energy equation of state (EoS) parameters. We proceed with the specific form of $f(R, L_m)$ gravity termed as $f(R, L_m)=\frac{R}{2}+L_{m}^α$. We derive the expansion rate in terms of the red-shift for two different forms of EoS parameter. In first model, EoS parameter varies inversely with the redshift and in second model, it involves the exponential form with the redshift. By using the Bayesian met…

This https://arxiv.org/abs/2409.02188 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Stochastic dark matter: Covariant Brownian motion from Planckian discreteness
Quantum gravity has long remained elusive from an observational standpoint. Developing effective cosmological models motivated by the fundamental aspects of quantum gravity is crucial for bridging theory with observations. One key aspect is the granularity of spacetime, which suggests that free particles would deviate from classical geodesics by following a covariant Brownian motion. This notion is further supported by swerves models in causal set theory, a discrete approach to quantum gravity.…

This https://arxiv.org/abs/2505.14446 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Light deflection in unified gravity and measurable deviation from general relativity
Light, though massless, does not travel in a perfectly straight line when it passes near a massive object. Instead, it follows the curvature of spacetime - a phenomenon predicted by Einstein's general theory of relativity. This effect, known as gravitational lensing, occurs because massive bodies like stars, galaxies, or black holes distort the fabric of spacetime around them, bending the path of light much like a lens bends rays in optics. In this work, we study gravitational lensing using the…