685 research outputs found
Agency is molecular: moved by being moved to moving or co-constitution in intra-active knowledge production
This practice-based PhD aims to intertwine theoretical research and artistic practice on the basis of knowledge production by conceptually thinking through motion, with movement informing the methodological counterpart in performative research settings. I argue that movement and the concept of motion, in their immanent potential for in/determinancy, transport possibilities of transversality that have been neglected in western Modernity. Both offer the means of moving beyond the bifurcated exceptionalism of Modernity's epistemology.
The project interrogates its own positioning from within by affirming embodied ways of knowing, which are marginalised within the rationalised epistemes in European Universalisms (Wallerstein). In doing so it also takes a stand against appropriation. From a feminist position, new materialism's situatedness (Haraway) and relational objectivity (Barad) are particularly suitable tools for a shift from within. The apparatus definitions of Agential Realism gather insights through agential cuts that provide a transient exteriority-within, allowing modifying the bounds of knowing from within.
The primary chapters examine the impact of practicing through theory and coalesce into a final experiment that reverses the process. Applied to the path of thoughts, movement's induction of changes to matter initiates an essential process of creating space for delinking (Mignolo/Walsh) and unlearning (Singh). The foundation of both practice- and theory-based approaches is Barad's notion of intra-active doing-being, which provides an understanding of agential intertwinement by approaching matter through and with interferences. In experiments, electronic devices were set to receive techno-sound-reverberations as diffractional concerns (noise), that transposed mattering (meaning) from co-constitutional forms.
These 'voices', enacted in material-discursive experiments of various entangled engagements in different molecular matterings (body-mind, nature-culture, non-human-human, other-self) are typically ignored, denied, or misunderstood by the notorious bifurcation of the western metaphysical matrix (Jackson). Listening to matter’s iterative performativity (Barad) disclosed uneven levels of capacity (Wilderson) within such non-interrogated generalisations as the flattening to 'we' of the Anthropocene discourse. This awareness of interferential reverberations demands a multidirectional pluriverse of capabilities, which compromises any one-world (Law) exceptionality
Signalling - at the molecular level
This text accompanies my performance piece at the exhibition, Hyphen – between art and research, in March 2019 at the Ambika P3 gallery. As with any other space, when entered, Ambika P3 becomes tangible in its relation and affectivity to both time and mattering. During the performance, the visible and audible specifics of the site become experiential through the diffraction of words and movement, intellect and sense, into contiguity. Throughout and beyond this text, movement practitioners engage with each other and the room, each from their perspective. Wearing e-textiles by the interface designer Gabriela Guasti Rocha, the performers will bring forward a normally imperceptible acoustic layer when moving through the space. Fitted with wireless transmitters, these costumes pick up buzzing sounds that are elicited by the interference of motion. The combination of these noises sparked by movement, together with speech, aims to underscore that thought and action emerge in their interference with the layers and diffractions of their surroundings. The unanticipated, simultaneous surfacing of various forms of knowing (in moving, speaking, listening) addresses motion as multi-layered. It levels this processual interweaving of what is commonly understood as antagonistic—theory and practice, body and mind, self and other—towards an interpretation of complementarity
Trembling cavities in the canonical approach
We present a canonical formalism facilitating investigations of the dynamical
Casimir effect by means of a response theory approach. We consider a massless
scalar field confined inside of an arbitaray domain , which undergoes
small displacements for a certain period of time. Under rather general
conditions a formula for the number of created particles per mode is derived.
The pertubative approach reveals the occurance of two generic processes
contributing to the particle production: the squeezing of the vacuum by
changing the shape and an acceleration effect due to motion af the boundaries.
The method is applied to the configuration of moving mirror(s). Some properties
as well as the relation to local Green function methods are discussed.
PACS-numbers: 12.20; 42.50; 03.70.+k; 42.65.Vh Keywords: Dynamical Casimir
effect; Moving mirrors; Cavity quantum field theory; Vibrating boundary
Axions in string theory — slaying the Hydra of dark radiation
It is widely believed that string theory easily allows for a QCD axion in the cosmologically favored mass range. The required small decay constant, f(a) << M-P, can be implemented by using a large compactification volume. This points to the Large Volume Scenario which in turn makes certain cosmological predictions: first, the closed string axion behaves similarly to a field-theoretic axion in the pre-inflationary scenario, i.e. the initial value can be tuned but one is constrained by isocurvature fluctuations. In addition, the volume represents a long-lived modulus that may lead to an early matter-dominated phase. Finally, the decay of the volume modulus to its own axion tends to overproduce dark radiation. In this paper we aim to carefully analyze the cosmology by studying models that not only allow for a QCD axion but also include inflation. Quite generally, limits on isocurvature fluctuations restrict us to relatively low-scale inflation, which in the present stringy context points to Kahler moduli inflation. As a novel feature we find that the lightest (volume) modulus couples strongly to the Higgs. It hence quickly decays to the SM, thus resolving the original dark radiation problem. This decay is much faster than that of the inflaton, implying that reheating is determined by the inflaton decay. The inflaton could potentially reintroduce a dark radiation problem since it decays to lighter moduli and their axions with equal rates. However, due its mixing with the QCD-saxion, the inflaton has also a direct decay rate to the SM, enhanced by the number of SM gauge bosons. This results in an amount of dark radiation that is consistent with present limits but potentially detectable in future measurements
Asexual Reproduction of Marine Invertebrate Embryos and Larvae
The life histories of marine invertebrates are incredibly diverse and provide a wealth of opportunities to develop and test hypotheses about how and why modes of reproduction, development, and behavior evolve within and among lineages. With respect to the evolution of reproductive and developmental mode, phylogenetic, adaptive, and functional hypotheses presented over the past century have predominantly focused on the evolution of reproductive traits (e.g., free spawning, brooding, encapsulation; nutritional mode of larvae (e.g., planktotrophy and lecithotrophy; and developmental form (e.g., larval morphology; direct and indirect development. Frequently, but not exclusively, these hypotheses have been tied to changes in per-offspring investment and influential models of per-offspring investment often serve as a framework for studies of the evolution of developmental modes. Phylogenetic assessment of the evolution of character states within lineages has revealed frequent shifts among life histories traits.https://scholarworks.wm.edu/asbookchapters/1011/thumbnail.jp
Axion interpretation of the PVLAS data?
The PVLAS collaboration has recently reported the observation of a rotation
of the polarization plane of light propagating through a transverse static
magnetic field. Such an effect can arise from the production of a light, m_A ~
meV, pseudoscalar coupled to two photons with coupling strength g_{A\gamma} ~
5x10^{-6} GeV^{-1}. Here, we review these experimental findings, discuss how
astrophysical and helioscope bounds on this coupling can be evaded, and
emphasize some experimental proposals to test the scenario.Comment: 4 pages, 1 figure, jpconf.cls, talk presented at the ninth
International Conference on Topics in Astroparticle and Underground Physics,
TAUP 2005, Zaragoza, Spain, September 10-14, 200
What measurable zero point fluctuations can(not) tell us about dark energy
We show that laboratory experiments cannot measure the absolute value of dark
energy. All known experiments rely on electromagnetic interactions. They are
thus insensitive to particles and fields that interact only weakly with
ordinary matter. In addition, Josephson junction experiments only measure
differences in vacuum energy similar to Casimir force measurements. Gravity,
however, couples to the absolute value. Finally we note that Casimir force
measurements have tested zero point fluctuations up to energies of ~10 eV, well
above the dark energy scale of ~0.01 eV. Hence, the proposed cut-off in the
fluctuation spectrum is ruled out experimentally.Comment: 4 page
New Experimental Limit on Photon Hidden-Sector Paraphoton Mixing
We report on the first results of a search for optical-wavelength photons
mixing with hypothetical hidden-sector paraphotons in the mass range between
10^-5 and 10^-2 electron volts for a mixing parameter greater than 10^-7. This
was a generation-regeneration experiment using the "light shining through a
wall" technique in which regenerated photons are searched for downstream of an
optical barrier that separates it from an upstream generation region. The new
limits presented here are approximately three times more sensitive to this
mixing than the best previous measurement. The present results indicate no
evidence for photon-paraphoton mixing for the range of parameters investigated.Comment: 9 pages, 3 figure
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