Self-interactions can stabilize excited boson stars

We study the time evolution of spherical, excited (i.e. nodeful) boson star models. We consider a model including quartic self-interactions, controlled by a coupling Λ. Performing non-linear simulations of the Einstein-(complex)-Klein-Gordon system, using as initial data equilibrium boson stars solutions of that system, we assess the impact of Λ in the stability properties of the boson stars. In the absence of self-interactions (Λ = 0), we observe the known behaviour that the excited stars in the (candidate) stable branch decay to a non-excited star without a node; however, we show that for large enough values of the self-interactions coupling, these excited stars do not decay (up to timescales of about t ∼104). The stabilization of the excited states for large enough self-interactions is further supported by evidence that the nodeful states dynamically form through the gravitational cooling mechanism, starting from dilute initial data. Our results support the healing power (against dynamical instabilities) of self-interactions, recently unveiled in the context of the non-axisymmetric instabilities of spinning boson stars.

Expressive Multilingual Writing

The purpose of this chapter reveals the healing power of writing at times of stress, turmoil, and crisis from multilingual perspectives. Writing relieves emotional chaos, stress, and even physical pain as evidenced by research. Multilingual writing is a process-based, complicated act that requires a series of intellectual stages to be developed as a skill. In parallel to this rationale, multilingual learners can generate creative spaces for their well-being and growth by using writing as a skill to express their emotions for easing feelings related to stress, turmoil, and crisis. This chapter encourages and models emotional or expressive writing as an innovative method to use in educational and health settings to allow creating novel experiences into language learning phases.

What does Kurort mean?

The article examines the evolvement of the Bulgarian word kurort in historical terms. The first part discusses the practices of using the healing power of nature from ancient times to the present day. Special attention is paid to balneology in Bulgaria as evidenced by numerous settlements named Banya, lit. ‘bath’. Next, an analysis is made of the word kurort and its dissimilarity from the corresponding English and French terms. The emergence of the concept of Kurort in the German language is associated with the general development of medicine from the XIV century onwards, when the medical terminology changed.

Matthew Arnold’s “Dover Beach’’: A Depiction of Victorian Doubt and Faith

Dissatisfied with his age Arnold turned towards Greek Culture and literature. Victorian age was an age of doubt and faith. Religious faith were in melting pot. Darwin’s ‘Origin Of Species’ (1859) shook the Victorian faith. Darwin questioned the very basic statement of ‘The Holy Bible’. Arnold considered literature as a weapon to established the broken faith of Victorians. He took Greek literature as reference to write literature. Arnold keenly observed Greek art and culture and find solace in it. He used Greek Art and Culture as the tool of morality and it has the healing power to wounded Victorian faith. Arnold’s ‘Dover Beach is a poetry of vanished past and vanished faith. Keywords: Reflective elegy, Vanished Faith, Victorian Doubt and Faith, Sea of faith.