Tootfinder

On a fibrational construction for optics, lenses, and Dialectica categories
Matteo Capucci, Bruno Gavranovi\'c, Abdullah Malik, Francisco Rios, Jonathan Weinberger
https://arxiv.org/abs/2403.16388

On a fibrational construction for optics, lenses, and Dialectica categories
Categories of lenses/optics and Dialectica categories are both comprised of bidirectional morphisms of basically the same form. In this work we show how they can be considered a special case of an overarching fibrational construction, generalizing Hofstra's construction of Dialectica fibrations and Spivak's construction of generalized lenses. This construction turns a tower of Grothendieck fibrations into another tower of fibrations by iteratively twisting each of the components, using the oppo…

This https://arxiv.org/abs/2306.02742 has been replaced.
link: https://scholar.google.com/scholar?q=a

Enhanced Robust Motion Control based on Unknown System Dynamics Estimator for Robot Manipulators
To achieve high-accuracy manipulation in the presence of unknown disturbances, we propose two novel efficient and robust motion control schemes for high-dimensional robot manipulators. Both controllers incorporate an unknown system dynamics estimator (USDE) to estimate disturbances without requiring acceleration signals and the inverse of inertia matrix. Then, based on the USDE framework, an adaptive-gain controller and a super-twisting sliding mode controller are designed to speed up the conve…

This https://arxiv.org/abs/2311.14285 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

Geometries with twisted spheres and non-abelian T-dualities
Spectral flow in two-dimensional field theories is known to correspond to geometrical twisting between two circles in the gravity dual. We generalize this operation to the geometries which have SO(k+1) x SO(k+1) isometries with k>1 and perform various non-abelian T-dualities of the resulting twisted backgrounds. Combination of non-abelian twists and dualities leads to a new solution generating technique in supergravity, and we apply it to the geometries dual to supersymmetric states in N=4 supe…

Spin Hall Effect: Symmetry Breaking, Twisting, and Giant Disorder Renormalization
David T. S. Perkins, Alessandro Veneri, Aires Ferreira
https://arxiv.org/abs/2403.15229

Spin Hall Effect: Symmetry Breaking, Twisting, and Giant Disorder Renormalization
Atomically-thin materials based on transition metal dichalcogenides and graphene offer a promising avenue for unlocking the mechanisms underlying the spin Hall effect (SHE) in heterointerfaces. Here, we develop a microscopic theory of the SHE for twisted van der Waals heterostructures that fully incorporates twisting and disorder effects, and illustrate the critical role of symmetry breaking in the generation of spin-Hall currents. We find that an accurate treatment of vertex corrections leads …

Infinite quantum twisting at the Cauchy horizon of rotating black holes
Christiane Klein, Mojgan Soltani, Marc Casals, Stefan Hollands
https://arxiv.org/abs/2402.14171

Infinite quantum twisting at the Cauchy horizon of rotating black holes
We present a numerical calculation of the expectation value of the quantum angular-momentum current flux density for a scalar field in the Unruh state near the inner horizon of a Kerr-de Sitter black hole. Our results indicate that this flux diverges as $V_-^{-1}$ in a suitable Kruskal coordinate such that $V_-=0$ at the inner horizon. Depending on the parameter values of the scalar field and black hole that we consider, and depending on the polar angle (latitude), this flux can have different …

This https://arxiv.org/abs/2403.11587 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

One Axis Twisting (OAT) spin squeezing for metrology
In this work we study One Axis Twisting (OAT) spin squeezing for metrology in the presence of decoherence. We study Linbladian evolution in the presence of both T_1 and T_2 (longitudinal and transverse relaxation processes). We show that spin squeezing can be an effective way to improve metrological accuracy even in the presence of decoherence for OAT squeezing. We show our results are not sensitive to inhomogeneity of the squeezing strength of the many spin OAT Hamiltonian and that very genera…

The twisting number of a ribbon knot is bounded below by its doubly slice genus
Vitalijs Brejevs, Peter Feller
https://arxiv.org/abs/2404.07619 https://

The twisting number of a ribbon knot is bounded below by its doubly slice genus
The twisting number of a ribbon knot $K$ is the minimal number of tangle replacements on the symmetry axis of $J \# -J$ for any knot $J$ that is required to produce a symmetric union diagram of $K$. We prove that the twisting number is bounded below by the doubly slice genus and produce examples of ribbon knots with arbitrarily high twisting number, addressing a problem of Tanaka. To this end, we establish a result of independent interest that the doubly slice genus of $K$ is bounded above by t…

Hello! Does anyone know if there is a brand that makes <Popit/Bubble Pop> fidget toys in a small form factor? I am looking for something my son could take to school to fiddle with instead of... erm twisting his glasses until the material stress cuts them in half
#pleaseboost #adhd…

One Axis Twisting (OAT) spin squeezing for metrology
Garry Goldstein
https://arxiv.org/abs/2403.11587 https://arxiv.org/pdf/2403.1158…

One Axis Twisting (OAT) spin squeezing for metrology
In this work we study One Axis Twisting (OAT) spin squeezing for metrology in the presence of decoherence. We study Linbladian evolution in the presence of both T_1 and T_2 (longitudinal and transverse relaxation processes). We show that spin squeezing can be an effective way to improve metrological accuracy even in the presence of decoherence for OAT squeezing. We show our results are not sensitive to inhomogeneity of the squeezing strength of the many spin OAT Hamiltonian and that very genera…

This https://arxiv.org/abs/2305.11557 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Multiplicities of Representations in Algebraic Families
In this short notes, we consider multiplicities of representations in general algebraic families, especially the upper semi-continuity of homological multiplicities and the locally constancy of Euler-Poincare numbers. This generalizes the main result of Aizenbud-Sayag for unramified twisting families.

Trump’s Ugly, Hateful Rants in Michigan Should Be Covered as a Scandal
The real story here is the way Trump is twisting select crimes to viciously smear undocumented immigrants across the board
https://newrepublic.com/article/180404/…

Trump’s Ugly, Hateful Rants in Michigan Should Be Covered as a Scandal
The real story here is the way Trump is twisting select crimes to viciously smear undocumented immigrants across the board.

#Democrats lock on #Latino vote that they took for granted has apparently expired, along with most of the party's former core principles.
While #Republicans are clearly defined, no one's quite sure what a Democrat is…

Latino voters are swinging back toward Trump and the GOP
Baker is a graduate student at Northwestern's Medill School of Journalism and a former active-duty Marine. CHARLESTON, S.C. – Inside a vendor’s booth at Charleston’s renowned City Market, Ingrid Ginn gripped a small pair of needle-nosed pliers, twisting a gold wire around itself to finish off a pair...

#PSA: If you're even remotely interested in good #PuzzleGames, do yourself a favor and play #Paquerette by @…

Save 20% on Paquerette Down the Bunburrows on Steam
The buns... you HAVE to capture them!! Think outside the bunburrow or get outsmarted by bunnies in this cute pathfinding-based puzzle game!

🫐 Berry Twist: a Twisting-Tube Soft Robotic Gripper for Blackberry Harvesting
#robots

Demon Nebula.
2 Free wallpapers for you to use!
Also uploaded to my Ko-fi completely uncompressed (Mastodon compresses images to 1280 px) for free here: #AIart

Demon Nebula. - Click to view on Ko-fi
Follow Be Aware on Ko-fi

This https://arxiv.org/abs/2201.03268 has been replaced.
link: https://scholar.google.com/scholar?q=a

Twisted $L^2$-Betti numbers of sofic groups
Wolfang Lück asked if twisted $L^2$-Betti numbers of a group are equal to the usual $L^2$-Betti numbers rescaled by the dimension of the twisting representation. We confirm this for sofic groups.

In those days, everyone talked about it. But hearing it with my own ears, and seeing the monitor behind him saying "COMMONLY AVAILABLE DISINFECTANTS (Bleach & Isopropyl Alcohol) work to kill the virus," chills me down to the bone. And the pos never stops yammering. Twisting words, scraping up nonsense to claim the office that he so covets. Twitter rightfully banned this superspreader of psychosis.
President Trump Suggests ‘Injecting’ Disinfectant as Coronavirus Cure

Moir\'e-modulated band gap and van Hove singularities in twisted bilayer germanene
Pantelis Bampoulis, Carolien Castenmiller, Dennis J. Klaassen, Jelle v. Mil, Paul L. de Boeij, Motohiko Ezawa, Harold J. W. Zandvliet
https://arxiv.org/abs/2403.14560

Moiré-modulated band gap and van Hove singularities in twisted bilayer germanene
Twisting bilayers of two-dimensional topological insulators has the potential to create unique quantum states of matter. Here, we successfully synthesized a twisted bilayer of germanene on Ge2Pt(101) with a 21.8$^o$ degrees twist angle, corresponding to a commensurate ($\sqrt{7} \times \sqrt{7}$) structure. Using scanning tunneling microscopy and spectroscopy, we unraveled the structural and electronic properties of this configuration, revealing a moiré-modulated band gap and a well-defined ed…

This https://arxiv.org/abs/2305.11557 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Multiplicities of Representations in Algebraic Families
In this short notes, we consider multiplicities of representations in general algebraic families, especially the upper semi-continuity of homological multiplicities and the locally constancy of Euler-Poincare numbers. This generalizes the main result of Aizenbud-Sayag for unramified twisting families.

This https://arxiv.org/abs/2205.13319 has been replaced.
link: https://scholar.google.com/scholar?q=a

Protocorks and monopole Floer homology
We introduce and study a class of compact 4-manifolds with boundary that we call protocorks. Any exotic pair of simply connected closed 4-manifolds is related by a protocork twist, moreover, any cork is supported by a protocork. We prove a theorem on the relative Seiberg-Witten invariants of a protocork before and after twisting and a splitting theorem on the Floer homology of protocork boundaries. As a corollary we improve a theorem by Morgan and Szabó regarding the variation of Seiberg-Witte…

This https://arxiv.org/abs/2311.04560 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Fast Generation of GHZ-like States Using Collective-Spin XYZ Model
The Greenberger-Horne-Zeilinger (GHZ) state is a key resource for quantum information processing and quantum metrology. The atomic GHZ state can be generated by one-axis twisting (OAT) interaction $H_{\mathrm{OAT}}=χJ_{z}^{2}$ with $χ$ the interaction strength, but it requires a long evolution time $χt=π/2$ and is thus seriously influenced by decoherence and losses. Here we propose a three-body collective-spin XYZ model which creates a GHZ-like state in a very short timescale $χt\sim \ln {…

Memory in cyclically crumpled sheets
Amit Dawadi, Arshad Kudrolli
https://arxiv.org/abs/2403.06918 https://arxiv.org/pdf/2403.06918…

Memory in cyclically crumpled sheets
We investigate the crumpling of a sheet as it is repeatedly crushed onto itself by rolling it into a cylinder and twisting it axially while allowing the end-to-end length to evolve freely. As deduced from its plastic deformations, the sheet creases and collapses into structures which repeat and sharpen over hundreds of cycles to a remarkable degree before forming new configurations. The observed metastablilty increases with applied cycles leading to recurrent structures over a significant range…

This https://arxiv.org/abs/2303.03175 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Residue maps, Azumaya algebras, and buildings
The goal of this note is to give an explicit formula for the residues of twists of the matrix algebra in terms of the twisting cocycle. Combined with the Fixed Point Theorem for actions of finite groups on affine buildings, this leads to a quick proof of the well-known characterization of unramified algebras in terms of Azumaya algebras.

This https://arxiv.org/abs/2401.12054 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Twisting asymptotic symmetries and algebraically special vacuum solutions
In this paper, we study asymptotic symmetries and algebraically special exact solutions in the Newman-Penrose formalism. Removing the hypersurface orthogonal condition in the well studied Newman-Unti gauge, we obtain a generic asymptotic solution space which includes all possible origins of propagating degree of freedom. The asymptotic symmetry of the generalized system extends the Weyl-BMS symmetry by two independent local Lorentz transformations with non-trivial boundary charges, which reveal…

This https://arxiv.org/abs/2401.10087 has been replaced.
initial toot: https://mastoxiv.page/@arX…

Correlating fluorescence microscopy, optical and magnetic tweezers to study single chiral biopolymers such as DNA
Biopolymer topology is critical for determining interactions inside cell environments, exemplified by DNA where its response to mechanical perturbation is as important as biochemical properties to its cellular roles. The dynamic structures of chiral biopolymers exhibit complex dependence with extension and torsion, however the physical mechanisms underpinning the emergence of structural motifs upon physiological twisting and stretching are poorly understood due to technological limitations in c…

The stable crossing number of a twist family of knots and the satellite crossing number conjecture
Kenneth L. Baker, Kimihiko Motegi
https://arxiv.org/abs/2404.05308

The stable crossing number of a twist family of knots and the satellite crossing number conjecture
Twisting a given knot $K$ about an unknotted circle $c$ a full $n \in \mathbb{N}$ times, we obtain a "twist family" of knots $\{ K_n \}$. Work of Kouno-Motegi-Shibuya implies that for a non-trivial twist family the crossing numbers $\{c(K_n)\}$ of the knots in a twist family grows unboundedly. However potentially this growth is rather slow and may never become monotonic. Nevertheless, based upon the apparent diagrams of a twist family of knots, one expects the growth should eventually be linear…

This https://arxiv.org/abs/2303.11918 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

3-braid knots with maximal 4-genus
We classify 3-braid knots whose topological 4-genus coincides with their Seifert genus, using McCoy's twisting method and the Xu normal form. In addition, we give upper bounds for the topological 4-genus of positive and strongly quasipositive 3-braid knots.

Aperiodic-quasiperiodic-periodic characteristics in twisted nested Moir\'e patterns and topological transitions
Peng Peng, Yuchen Peng, Aoqian Shi, Xiaogen Yi, Yizhou Wei, Jianjun Liu
https://arXiv.org/abs/2401.15849

Aperiodic-quasiperiodic-periodic characteristics in twisted nested Moiré patterns and topological transitions
The Moiré patterns generated by altering the structural parameters in a two or more layers of periodic materials, including single-layer structure, interlayer stacking, and twisting parameters, exhibit prosperous topological physical properties. However, the intricate characteristics of these Moiré patterns and their relationship with topological transitions remain unclear. In this Letter, based on the proposed twisted nested photonic crystal (TNPC), we derive its spatial geometric functions …