14 research outputs found
Grassmannian flows and applications to nonlinear partial differential equations
We show how solutions to a large class of partial differential equations with
nonlocal Riccati-type nonlinearities can be generated from the corresponding
linearized equations, from arbitrary initial data. It is well known that
evolutionary matrix Riccati equations can be generated by projecting linear
evolutionary flows on a Stiefel manifold onto a coordinate chart of the
underlying Grassmann manifold. Our method relies on extending this idea to the
infinite dimensional case. The key is an integral equation analogous to the
Marchenko equation in integrable systems, that represents the coodinate chart
map. We show explicitly how to generate such solutions to scalar partial
differential equations of arbitrary order with nonlocal quadratic
nonlinearities using our approach. We provide numerical simulations that
demonstrate the generation of solutions to
Fisher--Kolmogorov--Petrovskii--Piskunov equations with nonlocal
nonlinearities. We also indicate how the method might extend to more general
classes of nonlinear partial differential systems.Comment: 26 pages, 2 figure
Gender and sustainable livelihoods: linking gendered experiences of environment, community and self
In this essay I explore the economic, social,
environmental and cultural changes taking place in Bolsena,
Italy, where agricultural livelihoods have rapidly
diminished in the last two decades. I examine how gender
dynamics have shifted with the changing values and
livelihoods of Bolsena through three women’s narratives
detailing their gendered experiences of environment,
community and self. I reflect on these changes with Sabrina,
who is engaged in a feminist community-based
organization; Anna, who is running an alternative wine bar;
and Isabella, a jeweler, who is engaged in ecofeminist
practices. My analysis is based on concepts developed by
feminist political ecology: specifically, the theory of rooted
networks from Dianne Rocheleau, Donna Haraway’s concept
of naturecultures (and the work of J. K. Gibson-Graham
on new economic imaginaries emerging from the
politics of place. I aim to think with, reflect upon and
provoke from the ‘‘otherwise’’, taking into account the
lived relations entwining nature and gender. My article
looks at the interconnections of gender, environment and
livelihoods, attentive to the daily needs, embodied interactions
and labours of these three women as part of a
reappropriation, reconstruction and reinvention of Bolsena’s
lifeworld. By listening to the stories of their everyday
lives and struggles, I show the dynamic potential of the
politics of place and the efforts to build diverse economies
and more ethical economic and ecological relationships
based on gender-aware subjectivities and values
The Fredholm determinant method for discrete integrable evolution equations
TIB: RN 7349 (371) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman