Tootfinder

Faddeev-Jackiw Quantization of Classical Constrained Systems
Shaza Abdul Majid, Ansha S Nair, Saurabh Gupta
https://arxiv.org/abs/2507.22505 https://arxiv.…

Faddeev-Jackiw Quantization of Classical Constrained Systems
We accomplish the quantization of a few classical constrained systems à la (modified) Faddeev-Jackiw formalism. We analyze the constraint structure and obtain basic brackets of the theory. In addition, we disclose the gauge symmetries within the symplectic framework. We also provide new interpretation for Lagrange multipliers and outline a MATLAB implementation algorithm for symplectic formulation.

Constrained Dynamics on Eccentric Conic Orbits: Dirac-Bergmann and Hamilton-Jacobi Approaches
Alejandro G. Andarcia-Caballero, Jaime Manuel-Cabrera, Luis G. Romero-Hern\'andez, Jorge M. Paulin-Fuentes
https://arxiv.org/abs/2507.23271

Constrained Dynamics on Eccentric Conic Orbits: Dirac-Bergmann and Hamilton-Jacobi Approaches
In this work, we investigate a Lagrangian model describing a particle constrained to move along non-degenerate conic sections, parameterized by the orbital eccentricity \( e \). In the non-relativistic regime, we apply the Dirac--Bergmann algorithm to identify a set of four second-class constraints, compute the corresponding Dirac brackets, and isolate the true physical degrees of freedom. This procedure yields a unified Hamiltonian treatment of circular (\( e = 0 \)), elliptical (\( 0 < e < 1 …

Wife and I improvised a wardrobe from scrap stuff we had laying around. 0€ spent, some 3D printed parts (designed in #SolveSpace) hold everything together. That's why I love #3DPrinting. 💪

Handlebar brackets are done… I’ll mount the board on it tomorrow.
#maker #diy #3DPrinting

My project that I completed yesterday. An old patio umbrella base, a fence post from a big box store, two old wall brackets for flower baskets, a couple of bird feeders that were on sale at CanTire, and a repurposed squirrel baffle. About $100 in total cost, not including the black oil seed. It's positioned right outside our sunroom for bifd watching, by us and our cat Casper.
#DIY #Birdwatching #Gardening

Section 7 high school boys basketball tournament 2025 brackets, teams, schedule https://www.sportingnews.com/us/high-school/boys-basketball/news/section-7-high-school-…

BuzzFeed brackets are 100% accurate and do not lie. And only 5% agree with me? Go home 😂

Found a @… repost on #Imgur.

Psyquandle Brackets
Sam Nelson, Natsumi Oyamaguchi
https://arxiv.org/abs/2508.13331 https://arxiv.org/pdf/2508.13331

Psyquandle Brackets
We extend the notion of biquandle brackets to the case of psyquandles, defining quantum enhancements of the psyquandle counting invariant for singular knots and pseudoknots. We provide examples to illustrate the computation of these invariants, establishing that the enhancement is proper. We compute a few toy examples, noting that the true power of this infinite family of invariants lies in more computationally expensive larger-cardinality psyquandles and infinite coefficient rings.

A description of classical field equations using extensions of graded Poisson brackets
Manuel de Le\'on, Rub\'en Izquierdo-L\'opez
https://arxiv.org/abs/2507.04743

A description of classical field equations using extensions of graded Poisson brackets
As it is well-known, Poisson brackets play a fundamental role both in mechanics and in classical field theories. In this paper we develop a theory of extensions of graded Poisson brackets in graded Dirac manifolds. We then show how these extensions can be used to obtain the field equations of a particular theory as well as the evolution of forms of arbitrary order, in a similar way that ordinary Poisson brackets provide in mechanics.

Sometimes you forget to measure something precisely but it all still works out in the end.
#3DPrinting #DIY #maker

@… I explicitly do not discuss the Concrete Reference Syntax (i.e., the angle brackets) in this paper, but some other historical idiosyncrasies:
Michael Piotrowski (2019). “History and the future of markup”. In: Proceedings of XML Prague 2019 (Prague, Feb. 7–9, 2019). Ed. by Jiří Kosek, pp. 323–333. URL:

@… I explicitly do not discuss the Concrete Reference Syntax (i.e., the angle brackets) in this paper, but some other historical idiosyncrasies:
Michael Piotrowski (2019). “History and the future of markup”. In: Proceedings of XML Prague 2019 (Prague, Feb. 7–9, 2019). Ed. by Jiří Kosek, pp. 323–333. URL:

Biquandle Virtual Brackets and Virtual Knotoids
Neslihan G\"ug\"umc\"u, Hamdi Kayaslan
https://arxiv.org/abs/2507.07612 https://

Biquandle Virtual Brackets and Virtual Knotoids
In this paper, we introduce invariants of virtual knotoids based on biquandles and biquandle virtual brackets. We show that one of these invariants, namely biquandle virtual bracket matrix, is a proper enhancement of the other invariants introduced in this paper.

From Adler-Gelfand-Dickey Brackets to Logarithmic Dubrovin-Frobenius manifolds
Yassir Dinar
https://arxiv.org/abs/2506.11569 https://…

From Adler-Gelfand-Dickey Brackets to Logarithmic Dubrovin-Frobenius manifolds
We construct a new local Poisson bracket compatible with the second unconstrained Adler-Gelfand-Dickey bracket. The resulting bihamiltonian structure admits a dispersionless limit and the leading term defines a logarithmic Dubrovin-Frobenius manifold. Furthermore, we show that this Dubrovin-Frobenius manifold can be constructed on the orbits space of the standard representation of the permutation group.

Haha, Gmail has gotten dumber
I ordered a pizza (for takeout !)
and Gmail offered to "track your packages"

#TIL Weibo's custom emoji shortcodes are in square brackets 🤔 https://emojipedia.org/sina-weibo

Characteristic equations of linearized $\lambda R$ gravity
J. Aldair Pantoja-Gonzalez (Puebla U., Inst. Fis.), D. Vanessa Castro-Luna (Puebla U., Inst. Fis.), Alberto Escalante (Puebla U., Inst. Fis.)
https://arxiv.org/abs/2506.16603

Characteristic equations of linearized $λR$ gravity
A detailed Hamilton-Jacobi analysis for linearized $λR$ gravity is developed. The model is constructed by rewriting linearized gravity in terms of a parameter $λ$ and new variables. The set of all hamiltonians is identified successfully, and the fundamental differential is established. The non-involutive hamiltonians are eliminated, and the Hamilton-Jacobi generalized brackets are calculated. Such brackets are used to report the characteristic equations, and the counting of the number of degr…

This https://arxiv.org/abs/2506.00699 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

What is a double star-product?
Double Poisson brackets, introduced by M. Van den Bergh in 2004, are noncommutative analogs of the usual Poisson brackets in the sense of the Kontsevich-Rosenberg principle: they induce Poisson structures on the space of $N$-dimensional representations $\operatorname{Rep}_N(A)$ of an associative algebra $A$ for any $N$. The problem of deformation quantization of double Poisson brackets was raised by D. Calaque in 2010, and had remained open since then. In this paper, we address this problem b…

@… Yes, I agree, and I'd also love to get my hands on these drafts…
The author specifically mentions the angle brackets, which IMHO supports the assumption that the inital SGML working draft still used the GML syntax.

@… Yes, I agree, and I'd also love to get my hands on these drafts…
The author specifically mentions the angle brackets, which IMHO supports the assumption that the inital SGML working draft still used the GML syntax.

buy my shit https://www.ebay.com/itm/187320185087

Invariant Reduction for Partial Differential Equations. III: Poisson brackets
Kostya Druzhkov
https://arxiv.org/abs/2507.08213 https://

Invariant Reduction for Partial Differential Equations. III: Poisson brackets
We show that, under suitable conditions, finite-dimensional systems describing invariant solutions of partial differential equations (PDEs) inherit local Hamiltonian operators through the mechanism of invariant reduction, which applies uniformly to point, contact, and higher symmetries. The inherited operators endow the reduced systems with Poisson bivectors that relate constants of motion to symmetries. Applying the same mechanism to invariant conservation laws, we further show that the induce…

Supersymmetric M2-Brane Matrix Model with Restricted Volume-Preserving Deformations: Lorentz Covariance and BPS Spectrum
So Katagiri
https://arxiv.org/abs/2508.07259 https://

Supersymmetric M2-Brane Matrix Model with Restricted Volume-Preserving Deformations: Lorentz Covariance and BPS Spectrum
We present a novel supersymmetric Lorentz-covariant matrix model for M2-branes in M-theory, constructed via the framework of Restricted Volume-Preserving Deformations (RVPD) which is a residual symmetry from gauge-fixed volume-preserving diffeomorphisms. The model reformulates the supermembrane action entirely in terms of Nambu brackets, whose decomposition into Poisson brackets allows for a consistent matrix regularization that preserves both the Fundamental Identity and Lorentz covariance. Un…

What is a double star-product?
Nikita Safonkin
https://arxiv.org/abs/2506.00699 https://arxiv.org/pdf/2506.00699

What is a double star-product?
Double Poisson brackets, introduced by M. Van den Bergh in 2004, are noncommutative analogs of the usual Poisson brackets in the sense of the Kontsevich-Rosenberg principle: they induce Poisson structures on the space of $N$-dimensional representations $\operatorname{Rep}_N(A)$ of an associative algebra $A$ for any $N$. The problem of deformation quantization of double Poisson brackets was raised by D. Calaque in 2010, and had remained open since then. In this paper, we address this problem b…

A Lie Bracket on the Space of (Right) Biderivations of a Lie Algebra
Alfonso Di Bartolo, Gianmarco La Rosa
https://arxiv.org/abs/2507.12089 https://…

A Lie Bracket on the Space of (Right) Biderivations of a Lie Algebra
Derivations extend the concept of differentiation from functions to algebraic structures as linear operators satisfying the Leibniz rule. In Lie algebras, derivations form a Lie algebra via the commutator bracket of linear endomorphisms. Motivated by this, we study biderivations-bilinear maps capturing higher-order infinitesimal symmetries. This work focuses on right biderivations of Lie algebras, introducing Lie brackets on spaces of biderivations to explore their algebraic and geometric prope…

Classical r-matrix structure for elliptic Ruijsenaars chain and 1 1 field analogue of Ruijsenaars-Schneider model
D. Murinov, A. Zotov
https://arxiv.org/abs/2508.12656 https://

Classical r-matrix structure for elliptic Ruijsenaars chain and 1+1 field analogue of Ruijsenaars-Schneider model
The classical dynamical $r$-matrix structure for the periodic elliptic Ruijsenaars chain is described. The Poisson brackets for the monodromy matrix are calculated as well, thus providing Liouville integrability of the model. Next, we study its continuous non-relativistic limit and reproduce the Maillet type non-ultralocal $r$-matrix structure for the field analogue of the elliptic Calogero-Moser model.

Mastering Cosmological Amplitudes Using Generalized Ramanujan's Theorem
Prashanth Raman, Qinglin Yang
https://arxiv.org/abs/2508.13126 https://arxiv.or…

Mastering Cosmological Amplitudes Using Generalized Ramanujan's Theorem
We present a systematic method for computing cosmological amplitudes, including in-in correlators and wavefunction coefficients, in FRW spacetime. Specializing to cases with conformally-coupled external scalars and massive scalar exchanges, we introduce a decomposition into massive family trees, which capture the nested time structure common to these observables. We then evaluate these building blocks using the Method of Brackets (MoB), a multivariate extension of Ramanujan's master theorem tha…

Imposing quasineutrality on electrostatic plasmas via the Dirac theory of constraints
D. A. Kaltsas, J. W. Burby, P. J. Morrison, E. Tassi, G. N. Throumoulopoulos
https://arxiv.org/abs/2508.02389

Imposing quasineutrality on electrostatic plasmas via the Dirac theory of constraints
We present a method for imposing quasineutrality and, more generally, charge density conservation in the Vlasov-Poisson (VP) and Vlasov-Ampère (VA) systems, which describe electrostatic plasma dynamics, by applying the Dirac theory of constraints. Leveraging the Hamiltonian field formulations of the VP and VA models, we construct generalized Dirac brackets using the Dirac algorithm. The resulting constrained systems enforce charge density conservation, and consequently quasineutrality, through…

This https://arxiv.org/abs/2404.09284 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Deriving a GENERIC system from a Hamiltonian system
We reconsider the fundamental problem of coarse-graining infinite-dimensional Hamiltonian dynamics to obtain a macroscopic system which includes dissipative mechanisms. In particular, we study the thermodynamical implications concerning Hamiltonians, energy, and entropy and the induced geometric structures such as Poisson and Onsager brackets (symplectic and dissipative brackets). We start from a general finite-dimensional Hamiltonian system that is coupled linearly to an infinite-dimensional…

Crosslisted article(s) found for math.QA. https://arxiv.org/list/math.QA/new
[1/1]:
- Psyquandle Brackets
Sam Nelson, Natsumi Oyamaguchi
https://

Novikov equations for commuting differential operators of orders 3,4,5
G. B. Shabat, V. V. Sokolov, A. V. Tsiganov
https://arxiv.org/abs/2507.14978 https:/…

Novikov equations for commuting differential operators of orders 3,4,5
We consider Novikov equations for commutative ring generated by differential operators of orders 3,4,5. We present an explicit Hamiltonian form of these equations. Using the method of compatible Poisson brackets, we find a separation of variables on a hyperelliptic curve of genus 2 for the Novikov equations.

This https://arxiv.org/abs/2412.05110 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Revisiting semiclassical effective dynamics for quantum cosmology
We revise the technique of semiclassical effective dynamics, in particular reexamining the evaluation of Poisson structure of the so-called central moments capturing quantum corrections, providing a systematic, pedagogical, and efficient algorithm for evaluation of said structure. The resulting closed formulae for Poisson brackets involve less summatios than recent results in the literature, thus being more optimal for applications. Found formulae are then applied to a general class of isotropi…

Bouncing Bianchi Models with Deformed Commutation Relations
Gabriele Barca, Steffen Gielen
https://arxiv.org/abs/2507.01678 https://a…

Bouncing Bianchi Models with Deformed Commutation Relations
We study the anisotropic Bianchi I and Bianchi II models in vacuum in the framework of deformed commutation relations (DCRs). Working in a parametrisation of the spatial metric by a volume and two anisotropy variables, we propose modified Poisson brackets that for the volume alone reproduce the bounce dynamics of effective loop quantum cosmology (LQC), with additional modifications for anisotropy degrees of freedom. We derive effective Friedmann equations and observe cosmological bounces both i…