deterministic theory
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2021 ◽  
pp. 251484862110330
Author(s):  
Kyle Keeler

Anthropocene debate centers on the start-date and the cause of the geologic Epoch. One argument for the Epoch’s start-date is the “Early Anthropocene,” contending humanity “took control” of Earth systems during the Neolithic Revolution. Adherents contend agriculture contributed to rising carbon emissions and laid the groundwork for societal ills such as colonialism and extractive capitalism. Such a deterministic theory erases centuries of relational agriculture practiced by Indigenous peoples in the Americas. This article upsets the narrative of the “Early Anthropocene” that would mark all agriculture and agricultural societies as destructive and extractive, and instead offers embodied Indigenous narratives that view agriculture as a relational system of partnerships between humans and other-than-human beings over centuries. First, I trace the “Early Anthropocene” narrative from its origins with paleoclimatologist William Ruddiman to its contemporary adherents and show how such a theory lines-up with the narrative of the Christianized Biblical Fall. I show that “Early Anthropocene” theorists portray agriculture as society’s “ultimate sin,” wherein humans fall from a hunter–gatherer Eden and must toil to cultivate crops, eventually giving way to colonialism and extractive capitalism, ultimately causing environmental degradation and destruction and leading to a second coming of the hunter-gathering Eden. I then argue against such stories, tracing examples of relational agriculture practiced prior to settler colonization into our contemporary moment by Cherokee, Anishinaabe, Haudenosaunee, Western Apache, Karuk, Coast Salish, and Ponca peoples. Such stories show a pattern of missteps, understanding, and knowledge production between human groups and the more-than-human, rather than the environmental and societal destruction that Early Anthropocene theorists portray as the inevitable end of agricultural societies. This study disproves the agricultural “Early Anthropocene” as a starting point for Earth’s Epoch. It also presents relational environmental understanding through decolonized agriculture on repatriated land as a future method for interacting with the other-than-human environment.


Author(s):  
O. D. Street ◽  
D. Crisan

Spearheaded by the recent efforts to derive stochastic geophysical fluid dynamics models, we present a general framework for introducing stochasticity into variational principles through the concept of a semi-martingale driven variational principle and constraining the component variables to be compatible with the driving semi-martingale. Within this framework and the corresponding choice of constraints, the Euler–Poincaré equation can be easily deduced. We show that the deterministic theory is a special case of this class of stochastic variational principles. Moreover, this is a natural framework that enables us to correctly characterize the pressure term in incompressible stochastic fluid models. Other general constraints can also be incorporated as long as they are compatible with the driving semi-martingale.


2021 ◽  
Vol 232 ◽  
pp. 116289
Author(s):  
Jorge Herrera-Ordonez ◽  
Magali Cuatecontzi ◽  
Shirley Carro

2020 ◽  
Vol 29 (14) ◽  
pp. 2042003
Author(s):  
Shahar Hod

The Penrose strong cosmic censorship conjecture asserts that Cauchy horizons inside dynamically formed black holes are unstable to remnant matter fields that fall into the black holes. The physical importance of this conjecture stems from the fact that it provides a necessary condition for general relativity to be a truly deterministic theory of gravity. Determining the fate of the Penrose conjecture in nonasymptotically flat black hole spacetimes has been the focus of intense research efforts in recent years. In this paper, we provide a remarkably compact proof, which is based on Bekenstein’s generalized second law of thermodynamics, for the validity of the intriguing Penrose conjecture in physically realistic (dynamically formed) curved black hole spacetimes.


Author(s):  
Bjoern Bringmann

Abstract We study the derivative nonlinear wave equation $- \partial _{tt} u + \Delta u = |\nabla u|^2$ on $\mathbb{R}^{1 +3}$. The deterministic theory is determined by the Lorentz-critical regularity $s_L = 2$, and both local well-posedness above $s_L$ as well as ill-posedness below $s_L$ are known. In this paper, we show the local existence of solutions for randomized initial data at the super-critical regularities $s\geqslant 1.984$. In comparison to the previous literature in random dispersive equations, the main difficulty is the absence of a (probabilistic) nonlinear smoothing effect. To overcome this, we introduce an adaptive and iterative decomposition of approximate solutions into rough and smooth components. In addition, our argument relies on refined Strichartz estimates, a paraproduct decomposition, and the truncation method of de Bouard and Debussche.


2020 ◽  
Vol 68 ◽  
pp. 4612-4626
Author(s):  
Bariscan Yonel ◽  
Birsen Yazici

2019 ◽  
Vol 26 (4) ◽  
pp. 6-15
Author(s):  
Valeriy Nekrasov

Abstract The purpose of the paper is to create a method for studying nonlocal stability in the mean and in the mean square of the ship, positioned on the beam of an intensive wind–waves mode, which is based on the use of the correlation theory of random functions close to continuous Markov processes. With the help of this method and the integral formula of event probability, a method for determining the reliability indicator of the ship in respect of the existing wind–waves excitations of the operating area is formed. An example of investigating the nonlinear motion of the ship, determining its local and nonlocal stability in the first approximation of the theory of considered random functions, is given. Such approximation uses correlation theory with models of acting excitations represented by the generalised derivatives of the Wiener process. Moreover, special attention is paid to reflecting the connection of the proposed methods for investigating the ship stability under constantly acting random excitations with the traditional methods of studying ship stability at small and large inclinations. The established connection defines the proposed methods as a development of the traditional methods of ship stability deterministic theory during the transition to its formation in the class of random functions, with the addition to these methods of the missing link of determining the level of reliability of ships towards the acting wind–waves excitations of the operation area.


Author(s):  
Andrea Manrique-Yus ◽  
Elena Sellentin

Abstract We develop a fully non-invasive use of machine learning in order to enable open research on Euclid-sized data sets. Our algorithm leaves complete control over theory and data analysis, unlike many black-box like uses of machine learning. Focusing on a ‘3x2 analysis’ which combines cosmic shear, galaxy clustering and tangential shear at a Euclid-like sky coverage, we arrange a total of 348000 data points into data matrices whose structure permits not only an easy prediction by neural nets, but it additionally permits the essential removal from the data of patterns which the neural nets could not ‘understand’. The latter provides an often lacking mechanism to control and debias the inference of physics. The theoretical backbone to our neural net training can be any conventional (deterministic) theory code, where we chose CLASS. After training, we infer the seven parameters of a wCDM cosmology by Monte Carlo Markov sampling posteriors at Euclid-like precision within a day. We publicly provide the neural nets which memorise and output all 3x2 power spectra at a Euclid-like sky coverage and redshift binning.


Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 562 ◽  
Author(s):  
Shemer

The mechanisms governing the evolution of the wind-wave field in time and in space are not yet fully understood. Various theoretical approaches have been offered to model wind-wave generation. To examine their validity, detailed and accurate experiments under controlled conditions have to be carried out. Since it is next to impossible to get the required control of the governing parameters and to accumulate detailed data in field experiments, laboratory studies are needed. Extensive previously unavailable results on the spatial and temporal variation of wind waves accumulated in our laboratory under a variety of wind-forcing conditions and using diverse measuring techniques are reviewed. The spatial characteristics of the wind-wave field were determined using stereo video imaging. The turbulent airflow above wind waves was investigated using an X-hot film. The wave field under steady wind forcing as well as evolving from rest under impulsive loading was studied. An extensive discussion of the various aspects of wind waves is presented from a single consistent viewpoint. The advantages of the stochastic approach suggested by Phillips over the deterministic theory of wind-wave generation introduced by Miles are demonstrated. Essential differences between the spatial and the temporal analyses of wind waves’ evolution are discussed, leading to examination of the applicability of possible approaches to wind-wave modeling.


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