Classical many-body time crystals

Discrete time crystals are a many-body state of matter where the extensive system's dynamics are slower than the forces acting on it. Nowadays, there is a growing debate regarding the specific properties required to demonstrate such a many-body state, alongside several experimental realizations. In this work, we provide a simple and pedagogical framework by which to obtain many-body time crystals using parametrically coupled resonators. In our analysis, we use classical period-doubling bifurcation theory and present a clear distinction between single-mode time-translation symmetry breaking and a situation where an extensive number of degrees of freedom undergo the transition. We experimentally demonstrate this paradigm using coupled mechanical oscillators, thus providing a clear route for time crystals realizations in real materials.Comment: 23 pages, 5 figures, comments are welcom

«My Proof of Life»: el VIH como reificación de la metafísica negra en Homie de Danez Smith

Des de la seva aparició als anys huitanta, la literatura ha respost a la pandèmia de VIH/SIDA amb treballs que testimonien la devastadora pèrdua patida per milions de persones arreu del món. Després de la implementació de tractaments antiretrovirals efectius (TAR) a mitjans dels anys noranta, tanmateix, podria esperar-se que les experiències contemporànies de VIH canviaren la seva atenció des de l’afecció i el dol a emocions més “positives”. L’objectiu d’aquest article és considerar el potencial canvi de paradigma entre les noves generacions de gent seropositiva amb accés a TAR. A tal efecte, l’article explora l’aproximació lírica que Danez Smith fa a l’experiència racialitzada de VIH al segle XXI, intentant llegir aquesta experiència com constructiva en lloc de destructiva, sense deixar de banda la interseccionalitat, i en el context de l’afropessimisme i de l’optimisme queer.Since its onset in the 1980s, literature has responded to the HIV/AIDS pandemic with works that testify to the devastating loss imposed on millions of people worldwide. After the implementation of effective antiretroviral treatment (ART) in the mid-90s, however, contemporary experiences of HIV might be expected to diverge their attention from grief and mourning to more “positive” emotions. The aim of this paper is to consider such a potential paradigm shift among new generations of HIV+ people with access to ART. To do so, it explores Danez Smith’s lyric approach to a 21st-century racialized experience of HIV, attempting to read it as constructive rather than destructive, without leaving intersectionality aside, in light of both Afropessimism and Queer Optimism.Desde la aparición del VIH/SIDA en la década de 1980, la literatura ha respondido a la pandemia con trabajos que dan testimonio de la devastadora pérdida impuesta a millones de personas en todo el mundo. Sin embargo, después de la implementación de un tratamiento antirretroviral eficaz (TAR) a mediados de los años noventa, es de esperar que las experiencias contemporáneas del VIH desviaran su atención del dolor y el duelo hacia emociones más «positivas». El objetivo de este artículo es considerar este potencial cambio de paradigma entre las nuevas generaciones de personas VIH+ con acceso al TAR. Para ello explora el enfoque lírico que lleva a cabo Danez Smith de la experiencia racializada del VIH del siglo XXI, e intenta leer esta experiencia como constructiva en lugar de destructiva, sin dejar de lado la interseccionalidad y considerando en este contexto las perspectivas del afropesimismo y del optimismo queer

The Effects of Constant Time Delay in Teaching Recognition of Braille Words

The purpose of the study was to evaluate the use of a constant time delay procedure to teach core content words in braille to a student with a visual impairment. A multiple probe (conditions) across behaviors design was used to evaluate the effectiveness of the training and follow-up sessions. The results showed the procedure was effective in teaching core content braille words within a resource setting and the student was able to generalize the information to an inclusive setting

Internal Finance and Firm Investment

We examine the neoclassical investment model using a panel of U.S. manufacturing firms. The standard model with no financing constraints cannot be rejected for firms with high (pre-sample) dividend payouts. However, it is decisively rejected for firms with low (pre-sample) payouts (firms we expect to face financing constraints). Hem, investment is sensitive to both firm cash flow and macroeconomic credit conditions, holding constant investment opportunities. Sample splits based on firm size or maturity do not produce such distinctions. The latter comparison identifies firms where "free-cash-flow" problems might be expected to produce correlations between investment and cash flow.

"I Got the Cell Count Blues:" Danez Smith, HIV, and the Legacy of the Black Arts Movement

This paper connects Danez Smith’s collection of poems Don’t Call Us Dead (2017) to writing by the poet’s predecessors in the Black Arts Movement. I argue that Smith’s expression of HIV in their poetry continues and updates the denunciation of mass incarceration of, as well as structural violence against, non-white US citizens. My goal is to analyze intertextuality and the main topoi in Smith’s poetry as elements contributing to the extension of the BAM’s attempt to raise awareness and create Black self-determination and nationhood (Neal 1969). To do so, I read Smith’s work in light of contemporary thought, focusing on Judith Butler’s (2004) ideas of grievability, indefinite detention, and the hierarchies of death