scholarly journals NLO gravitational quartic-in-spin interaction

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Michèle Levi ◽  
Fei Teng

Abstract In this paper we derive for the first time the complete gravitational quartic-in-spin interaction of generic compact binaries at the next-to-leading order in the post-Newtonian (PN) expansion. The derivation builds on the effective field theory for gravitating spinning objects, and its recent extensions, in which new type of worldline couplings should be considered, as well as on the extension of the effective action of a spinning particle to quadratic order in the curvature. The latter extension entails a new Wilson coefficient that appears in this sector. This work pushes the precision frontier with spins at the fifth PN (5PN) order for maximally-spinning compact objects, and at the same time informs us of the gravitational Compton scattering with higher spins.

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Michèle Levi ◽  
Stavros Mougiakakos ◽  
Mariana Vieira

Abstract In this work we derive for the first time the complete gravitational cubic-in-spin effective action at the next-to-leading order in the post-Newtonian (PN) expansion for the interaction of generic compact binaries via the effective field theory for gravitating spinning objects, which we extend in this work. This sector, which enters at the fourth and a half PN (4.5PN) order for rapidly-rotating compact objects, completes finite-size effects up to this PN order, and is the first sector completed beyond the current state of the art for generic compact binary dynamics at the 4PN order. At this order in spins with gravitational nonlinearities we have to take into account additional terms, which arise from a new type of worldline couplings, due to the fact that at this order the Tulczyjew gauge for the rotational degrees of freedom, which involves the linear momentum, can no longer be approximated only in terms of the four-velocity. One of the main motivations for us to tackle this sector is also to see what happens when we go to a sector, which corresponds to the gravitational Compton scattering with quantum spins larger than one, and maybe possibly also get an insight on the inability to uniquely fix its amplitude from factorization when spins larger than two are involved. A general observation that we can clearly make already is that even-parity sectors in the order of the spin are easier to handle than odd ones. In the quantum context this corresponds to the greater ease of dealing with bosons compared to fermions.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Michèle Levi ◽  
Andrew J. McLeod ◽  
Matthew von Hippel

Abstract We compute the N3LO gravitational quadratic-in-spin interactions at G4 in the post-Newtonian (PN) expansion via the effective field theory (EFT) of gravitating spinning objects for the first time. This result contributes at the 5PN order for maximally-spinning compact objects, adding the spinning case to the static sector at this PN accuracy. This sector requires extending the EFT of a spinning particle beyond linear order in the curvature to include higher-order operators quadratic in the curvature that are relevant at this PN order. We make use of a diagrammatic expansion in the worldline picture, and rely on our recent upgrade of the EFTofPNG code, which we further extend to handle this sector. Similar to the spin-orbit sector, we find that the contributing three-loop graphs give rise to divergences, logarithms, and transcendental numbers. However, in this sector all of these features conspire to cancel out from the final result, which contains only finite rational terms.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Michèle Levi ◽  
Andrew J. McLeod ◽  
Matthew von Hippel

Abstract In this paper we derive for the first time the N3LO gravitational spin-orbit coupling at order G4 in the post-Newtonian (PN) approximation within the effective field theory (EFT) of gravitating spinning objects. This represents the first computation in a spinning sector involving three-loop integration. We provide a comprehensive account of the topologies in the worldline picture for the computation at order G4. Our computation makes use of the publicly-available EFTofPNG code, which is extended using loop-integration techniques from particle amplitudes. We provide the results for each of the Feynman diagrams in this sector. The three-loop graphs in the worldline picture give rise to new features in the spinning sector, including divergent terms and logarithms from dimensional regularization, as well as transcendental numbers, all of which survive in the final result of the topologies at this order. This result enters at the 4.5PN order for maximally-rotating compact objects, and together with previous work in this line, paves the way for the completion of this PN accuracy.


2021 ◽  
pp. 232102222098516
Author(s):  
Dipankar Das

The paper puts forth a notion and derives a special type of production function where labour is an indivisible factor and is in the integer space. Thus, Newtonian calculus is not an appropriate method of deriving the marginal value because limit point does not exist. This shows that indivisibility determines the output elasticity. In the first part, the paper propounds a notion regarding how indivisibility determines curvature of the production function. In the second part, the paper incorporates the findings within a production function and derives a new type accordingly. Moreover, it formally derives the standard wage equation considering all the entitlements of labour, namely (a) normal wages, (b) interest and (c) rent of ability. So far, no such mathematical proof is there to support this wage composition. This paper, for the first time, derives this wage equation considering indivisibility of labour. JEL Classifications: J23, J24, J31, D24, C61, E24, L8


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Zhengwen Liu ◽  
Rafael A. Porto ◽  
Zixin Yang

Abstract Building upon the worldline effective field theory (EFT) formalism for spinning bodies developed for the Post-Newtonian regime, we generalize the EFT approach to Post-Minkowskian (PM) dynamics to include rotational degrees of freedom in a manifestly covariant framework. We introduce a systematic procedure to compute the total change in momentum and spin in the gravitational scattering of compact objects. For the special case of spins aligned with the orbital angular momentum, we show how to construct the radial action for elliptic-like orbits using the Boundary-to-Bound correspondence. As a paradigmatic example, we solve the scattering problem to next-to-leading PM order with linear and bilinear spin effects and arbitrary initial conditions, incorporating for the first time finite-size corrections. We obtain the aligned-spin radial action from the resulting scattering data, and derive the periastron advance and binding energy for circular orbits. We also provide the (square of the) center-of-mass momentum to $$ \mathcal{O}\left({G}^2\right) $$ O G 2 , which may be used to reconstruct a Hamiltonian. Our results are in perfect agreement with the existent literature, while at the same time extend the knowledge of the PM dynamics of compact binaries at quadratic order in spins.


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Walter D. Goldberger ◽  
Ira Z. Rothstein

Abstract Using Effective Field Theory (EFT) methods, we compute the effects of horizon dissipation on the gravitational interactions of relativistic binary black hole systems. We assume that the dynamics is perturbative, i.e it admits an expansion in powers of Newton’s constant (post-Minkowskian, or PM, approximation). As applications, we compute corrections to the scattering angle in a black hole collision due to dissipative effects to leading PM order, as well as the post-Newtonian (PN) corrections to the equations of motion of binary black holes in non-relativistic orbits, which represents the leading order finite size effect in the equations of motion. The methods developed here are also applicable to the case of more general compact objects, eg. neutron stars, where the magnitude of the dissipative effects depends on non-gravitational physics (e.g, the equation of state for nuclear matter).


2010 ◽  
Vol 192 (22) ◽  
pp. 5866-5873 ◽  
Author(s):  
Hsu-Yuan Fu ◽  
Yu-Cheng Lin ◽  
Yung-Ning Chang ◽  
Hsiaochu Tseng ◽  
Ching-Che Huang ◽  
...  

ABSTRACT Microbial rhodopsins, a diverse group of photoactive proteins found in Archaea, Bacteria, and Eukarya, function in photosensing and photoenergy harvesting and may have been present in the resource-limited early global environment. Four different physiological functions have been identified and characterized for nearly 5,000 retinal-binding photoreceptors, these being ion transporters that transport proton or chloride and sensory rhodopsins that mediate light-attractant and/or -repellent responses. The greatest number of rhodopsins previously observed in a single archaeon had been four. Here, we report a newly discovered six-rhodopsin system in a single archaeon, Haloarcula marismortui, which shows a more diverse absorbance spectral distribution than any previously known rhodopsin system, and, for the first time, two light-driven proton transporters that respond to the same wavelength. All six rhodopsins, the greatest number ever identified in a single archaeon, were first shown to be expressed in H. marismortui, and these were then overexpressed in Escherichia coli. The proteins were purified for absorption spectra and photocycle determination, followed by measurement of ion transportation and phototaxis. The results clearly indicate the existence of a proton transporter system with two isochromatic rhodopsins and a new type of sensory rhodopsin-like transducer in H. marismortui.


2010 ◽  
Vol 97-101 ◽  
pp. 64-68
Author(s):  
Jian Chen ◽  
Jin Wang ◽  
Guo Dong Lu ◽  
Zheng Qi Ling

High- precision and large scale are the developing trend for injection molding machine clamping system .This paper compared the characteristics of three-platen toggle and dual-platen hydraulic clamping system. The key impact factors that effecting plastic parts` precision from clamping system were discussed systematically first time. Based on these analyses, a new clamping system has been proposed and manufactured to improve the plastics parts` precision, including three new technologies: new type dual-platen structure, parallelism adaptive correction technology and numerical controlled hydraulic servo system technology. It has been applied in practical machine successfully, and experiment result proves that it is effective enough to satisfying the high-precision molding of large plastics parts.


1968 ◽  
Vol 9 (1) ◽  
pp. 119-146 ◽  
Author(s):  
J. M. Lonsdale

This paper attempts to provide a frame of reference for evaluating the role of ordinary rural Africans in national movements, in the belief that scholarly preoccupation with élites will only partially illumine the mainsprings of nationalism. Kenya has been taken as the main field of enquiry, with contrasts and comparisons drawn from Uganda and Tanganyika. The processes of social change are discussed with a view to establishing that by the end of the colonial period one can talk of peasants rather than tribesmen in some of the more progressive areas. This change entailed a decline in the leadership functions of tribal chiefs who were also the official agents of colonial rule, but did not necessarily mean the firm establishment of a new type of rural leadership. The central part of the paper is taken up with an account of the competition between these older and newer leaderships, for official recognition rather than a mass following. A popular following was one of the conditions for such recognition, but neither really achieved this prior to 1945 except in Kikuyuland, and there the newer leaders did not want official recognition. After 1945 the newer leadership, comprising especially traders and officials of marketing co-operatives, seems everywhere to have won a properly representative position, due mainly to the enforced agrarian changes which brought the peasant face to face with the central government, perhaps for the first time. This confrontation, together with the experience of failure in earlier and more local political activity, resulted in a national revolution coalescing from below, co-ordinated rather than instigated by the educated élite.


2021 ◽  
Vol 9 (SPE2) ◽  
Author(s):  
Svetlana Strokina ◽  
Lenie Taymazova ◽  
Elvina Useinova ◽  
Ruslan Adonin

1922-1924 was a fruitful period of Maxim Gorky's literature work. It is related to searching a new art form. The cycle “Stories of 1922-1924” is an expressive example of “new prose”. For the first time, the hermit character appeared in the cycle “Stories of 1922-1924”. From the point of view of generally recognized morality and the Church, the new type of character is ambiguous. It is characterized by both sinfulness and holiness.


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