pinecone/core-2020-05-10-deduplication huggingface dataset:
Supernova Remnants as Clues to Their Progenitors

Supernovae shape the interstellar medium, chemically enrich their host
galaxies, and generate powerful interstellar shocks that drive future
generations of star formation. The shock produced by a supernova event acts as
a type of time machine, probing the mass loss history of the progenitor system
back to ages of $\sim$ 10 000 years before the explosion, whereas supernova
remnants probe a much earlier stage of stellar evolution, interacting with
material expelled during the progenitor's much earlier evolution. In this
chapter we will review how observations of supernova remnants allow us to infer
fundamental properties of the progenitor system. We will provide detailed
examples of how bulk characteristics of a remnant, such as its chemical
composition and dynamics, allow us to infer properties of the progenitor
evolution. In the latter half of this chapter, we will show how this exercise
may be extended from individual objects to SNR as classes of objects, and how
there are clear bifurcations in the dynamics and spectral characteristics of
core collapse and thermonuclear supernova remnants. We will finish the chapter
by touching on recent advances in the modeling of massive stars, and the
implications for observable properties of supernovae and their remnants.Comment: A chapter in "Handbook of Supernovae" edited by Athem W. Alsabti and
  Paul Murdin (18 pages, 6 figures
The intrinsic bispectrum of the Cosmic Microwave Background [PhD thesis]

The CMB bispectrum is a potential window on exciting new physics, as it is
sensitive to the non-Gaussian features in the primordial fluctuations, the same
fluctuations that evolved into today's planets, stars and galaxies. However,
this invaluable information is potentially screened, as not all of the observed
non-Gaussianity is of primordial origin. Indeed, a bispectrum arises even for
perfectly Gaussian initial conditions due to non-linear dynamics, such as CMB
photons scattering off free electrons and propagating in an inhomogeneous
Universe. In this thesis, I introduce the reader to this intrinsic bispectrum
in a pedagogic way, building up from the standard model of cosmology and from
cosmological perturbation theory, the tool cosmologists use to unravel the
history of the cosmos. In doing so, I introduce $\text{SONG}$, a new and
efficient code for solving the second-order Einstein and Boltzmann equations.
Next, I move on to answer the crucial question: is the intrinsic bispectrum
going to screen the primordial signal in the CMB? Using $\text{SONG}$ I compute
the intrinsic bispectrum and shows how its contamination leads to a small bias
in the estimates of primordial non-Gaussianity, a great news for the prospect
of using CMB data to probe primordial non-Gaussianity.Comment: The thesis' approach is pedagogical, ideal for a PhD student. The
  SONG code is available at https://github.com/coccoinomane/song/ . Feel free
  to contact me at guido.pettinari@gmail.com <mailto:guido.pettinari@gmail.com>
  ! UPDATE: Fixed typos & updated references; thesis published in Springer
  Theses Series at http://www.springer.com/gp/book/9783319218816
  <http://www.springer.com/gp/book/9783319218816> ; check out new exciting
  results with polarisation in arXiv:1406.2981
Quantum Information Processing with Finite Resources - Mathematical
  Foundations

One of the predominant challenges when engineering future quantum information
processors is that large quantum systems are notoriously hard to maintain and
control accurately. It is therefore of immediate practical relevance to
investigate quantum information processing with limited physical resources, for
example to ask: How well can we perform information processing tasks if we only
have access to a small quantum device? Can we beat fundamental limits imposed
on information processing with classical resources? This book will introduce
the reader to the mathematical framework required to answer such questions.
  A strong emphasis is given to information measures that are essential for the
study of devices of finite size, including R\'enyi entropies and smooth
entropies. The presentation is self-contained and includes rigorous and concise
proofs of the most important properties of these measures. The first chapters
will introduce the formalism of quantum mechanics, with particular emphasis on
norms and metrics for quantum states. This is necessary to explore quantum
generalizations of R\'enyi divergence and conditional entropy, information
measures that lie at the core of information theory. The smooth entropy
framework is discussed next and provides a natural means to lift many arguments
from information theory to the quantum setting. Finally selected applications
of the theory to statistics and cryptography are discussed.Comment: 135 pages, partly based on arXiv:1203.2142, v3: minor fixes,
  published version, SpringerBriefs in Mathematical Physics (2016
Using Monte Carlo method for searching partitionings of hard variants of
  Boolean satisfiability problem

In this paper we propose the approach for constructing partitionings of hard
variants of the Boolean satisfiability problem (SAT). Such partitionings can be
used for solving corresponding SAT instances in parallel. For the same SAT
instance one can construct different partitionings, each of them is a set of
simplified versions of the original SAT instance. The effectiveness of an
arbitrary partitioning is determined by the total time of solving of all SAT
instances from it. We suggest the approach, based on the Monte Carlo method,
for estimating time of processing of an arbitrary partitioning. With each
partitioning we associate a point in the special finite search space. The
estimation of effectiveness of the particular partitioning is the value of
predictive function in the corresponding point of this space. The problem of
search for an effective partitioning can be formulated as a problem of
optimization of the predictive function. We use metaheuristic algorithms
(simulated annealing and tabu search) to move from point to point in the search
space. In our computational experiments we found partitionings for SAT
instances encoding problems of inversion of some cryptographic functions.
Several of these SAT instances with realistic predicted solving time were
successfully solved on a computing cluster and in the volunteer computing
project SAT@home. The solving time agrees well with estimations obtained by the
proposed method.Comment: The reduced version of this paper was accepted for publication in
  proceedings of the PaCT 2015 conference (LNCS Vol. 9251). arXiv admin note:
  substantial text overlap with arXiv:1411.543
Cosmic Reionization and the First Nonlinear Structures in the Universe

In this introductory chapter, we outline expectations for when and how the
hydrogen and helium atoms in the universe turned from neutral to ionized,
focusing on the earliest, least well understood stages, and emphasizing the
most important open questions. We include a historical summary, and highlight
the role of reionization as one of the few milestones in the evolution of the
universe since the Big Bang, and its status as a unique probe of the beginning
stages of structure formation.Comment: 21 pages with 157 references. Book chapter in "Understanding the
  Epoch of Cosmic Reionization: Challenges and Progress", Springer
  International Publishing, Ed. Andrei Mesinger, ISBN 978-3-319-21956-
Modeling the Intergalactic Medium during the Epoch of Reionization

A major goal of observational and theoretical cosmology is to observe the
largely unexplored time period in the history of our universe when the first
galaxies form, and to interpret these measurements. Early galaxies dramatically
impacted the gas around them in the surrounding intergalactic medium (IGM) by
photoionzing the gas during the Epoch of Reionization (EoR). This epoch likely
spanned an extended stretch in cosmic time: ionized regions formed and grew
around early generations of galaxies, gradually filling a larger and larger
fraction of the volume of the universe. At some time -- thus far uncertain, but
within the first billion years or so after the big bang -- essentially the
entire volume of the universe became filled with ionized gas. The properties of
the IGM provide valuable information regarding the formation time and nature of
early galaxy populations, and many approaches for studying the first luminous
sources are hence based on measurements of the surrounding intergalactic gas.
The prospects for improved reionization-era observations of the IGM and early
galaxy populations over the next decade are outstanding. Motivated by this, we
review the current state of models of the IGM during reionization. We focus on
a few key aspects of reionization-era phenomenology and describe: the redshift
evolution of the volume-averaged ionization fraction, the properties of the
sources and sinks of ionizing photons, along with models describing the spatial
variations in the ionization fraction, the ultraviolet radiation field, the
temperature of the IGM, and the gas density distribution.Comment: Book Chapter in "Understanding the Epoch of Cosmic Reionization:
  Challenges and Progress", Springer International Publishing, Ed. Andrei
  Mesinger, ISBN 978-3-319-21956-
Star Formation for Predictive Primordial Galaxy Formation

The elegance of inflationary cosmology and cosmological perturbation theory
ends with the formation of the first stars and galaxies, the initial sources of
light that launched the phenomenologically rich process of cosmic reionization.
Here we review the current understanding of early star formation, emphasizing
unsolved problems and technical challenges. We begin with the first generation
of stars to form after the Big Bang and trace how they influenced subsequent
star formation. The onset of chemical enrichment coincided with a sharp
increase in the overall physical complexity of star forming systems. Ab-initio
computational treatments are just now entering the domain of the predictive and
are establishing contact with local observations of the relics of this ancient
epoch.Comment: Book chapter in "Understanding the Epoch of Cosmic Reionization:
  Challenges and Progress", Springer International Publishing, Ed. Andrei
  Mesinger, ISBN 978-3-319-21956-
High-Redshift Galaxy Surveys and the Reionization of the Universe

Star-forming galaxies in the early universe provide us with perhaps the most
natural way of explaining the reionization of the universe. Current
observational results are sufficiently comprehensive, as to allow us to
approximately calculate how the ionizing radiation from galaxies varies as a
function of cosmic time. Important uncertainties in modeling reionization by
galaxies revolve around the escape fraction and its luminosity and redshift
dependence, a possible truncation of the galaxy luminosity function at the
faint end, and an evolution in the production efficiency of Lyman-continuum
photons with cosmic time. Despite these uncertainties, plausible choices for
these parameters naturally predict a cosmic ionizing emissivity at z~6-10 whose
evolution and overall normalization is in excellent agreement with that derived
from current observational constraints. This strongly suggests that galaxies
provide the necessary photons to reionize the universe.Comment: 37 pages, 14 figures, Book chapter in "Understanding the Epoch of
  Cosmic Reionization: Challenges and Progress", Springer International
  Publishing, Ed. Andrei Mesinger, ISBN 978-3-319-21956-1, corrected a few
  minor typo
Constraining Reionization with Lyman Alpha Emitting Galaxies

Neutral diffuse intergalactic gas that existed during the Epoch of
Reionization (EoR) suppresses Lyman Alpha (Lya) flux emitted by background
galaxies. In this chapter I summarise the increasing observational support for
the claim that Lya photons emitted by galaxies at z>6 are suppressed by
intervening HI gas. I describe key physical processes that affect Lya transfer
during the EoR. I argue that in spite of the uncertainties associated with this
complex multiscale problem, the data on Lya emitting galaxies at z=0-6 strongly
suggests that the observed reduction in Lya flux from galaxies at z>6 is due to
additional intervening HI gas. The main question is what fraction of this
additional HI gas is in the diffuse neutral IGM. I summarise how future surveys
on existing and upcoming instruments are expected to reduce existing
observational uncertainties enormously. With these improved data we will likely
be able to nail down reionization with Lya emitting galaxies.Comment: 17 pages, 6 figures. Book chapter in "Understanding the Epoch of
  Cosmic Reionization: Challenges and Progress", Springer International
  Publishing, Ed. Andrei Mesinger, ISBN 978-3-319-21956-
Metal Enrichment in the Reionization Epoch

The presence of elements heavier than helium ("metals") is of fundamental
importance for a large number of astrophysical processes occurring in planet,
star and galaxy formation; it also affects cosmic structure formation and
evolution in several ways. Even a small amount of heavy elements can
dramatically alter the chemistry of the gas, opening the path to complex
molecules. Metals might enhance the ability of the gas to radiate away its
thermal energy, thus favoring the formation of gravitationally bound objects;
they can also condensate in a solid phase (dust grains), partly or totally
blocking radiation from luminous sources. Finally, they represent useful
tracers of energy deposition by stars and probe the physical properties of the
environment by absorption or emission lines. Last, but certainly not least,
life -- as we know it on Earth -- is tightly related to the presence of at
least some of the heavy elements. In this pedagogical review I will concentrate
on the connection between early metal enrichment and cosmic reionization. As we
will see these two processes are intimately connected and their joint study
might turn out to be fundamental in understanding the overall evolution of the
Universe during the first billion years after the Big Bang, an epoch
corresponding to redshifts z>6.Comment: Book chapter in Understanding the Epoch of Cosmic Reionization:
  Challenges and Progress, Springer International Publishing, Ed. Andrei
  Mesinger, ISBN 978-3-319-21956-1. arXiv admin note: text overlap with
  arXiv:astro-ph/0007248 by other author
Quasars as probes of cosmological reionization

Quasars are the most luminous non-transient sources in the epoch of
cosmological reionization (i.e., which ended a billion years after the Big
Bang, corresponding to a redshift of z ~ 5), and are powerful probes of the
inter-galactic medium at that time. This review covers current efforts to
identify high-redshift quasars and how they have been used to constrain the
reionization history. This includes a full description of the various processes
by which neutral hydrogen atoms can absorb/scatter ultraviolet photons, and
which lead to the Gunn-Peterson effect, dark gap and dark pixel analyses,
quasar near zones and damping wing absorption. Finally, the future prospects
for using quasars as probes of reionization are described.Comment: Book chapter in 'Understanding the Epoch of Cosmic Reionization:
  Challenges and Progress', Springer International Publishing, ed. Andrei
  Mesinger, ISBN 978-3-319-21956-
Observing the Epoch of Reionization with the Cosmic Microwave Background

We review the observable consequences of the epoch of reionization (EoR) on
the cosmic microwave background (CMB), and the resulting constraints on the
EoR. We discuss how Thomson scattering with the free electrons produced during
EoR equates to an optical depth for CMB photons. The optical depth measurements
from the WMAP and Planck satellites, using large-scale CMB polarization power
spectra, is one of the few current constraints on the timing of cosmic
reionization. We also present forecasts for the precision with which the
optical depth will be measured by future satellite missions. Second, we
consider the kinematic Sunyaev-Zel'dovich (kSZ) effect, and how the kSZ power
spectrum depends on the duration of reionization. We review current
measurements of the kSZ power and forecasts for future experiments. Finally, we
mention proposals to look for spectral distortions in the CMB that are related
to the electron temperature at EoR, and ideas to map the variations in the
optical depth across the sky.Comment: Book chapter in "Understanding the Epoch of Cosmic Reionization:
  Challenges and Progress", Springer International Publishing, Ed. Andrei
  Mesinger, ISBN 978-3-319-21956-
The 21-cm Line as a Probe of Reionization

One of the most exciting probes of the early phases of structure formation
and reionization is the spin-flip line of neutral hydrogen, with a rest
wavelength of 21 cm. This chapter introduces the physics of this transition and
the astrophysical parameters upon which it depends, including discussions of
the radiation fields that permeate the intergalactic medium that fix the
brightness of this transition. We describe the critical points in the evolution
of the 21-cm background and focus on the sky-averaged brightness and the power
spectrum as representative measurements. Finally, we include a discussion of
observations and the challenges they face in the near future.Comment: Book chapter in "Understanding the Epoch of Cosmic Reionization:
  Challenges and Progress", Springer International Publishing, Ed. Andrei
  Mesinger, ISBN 978-3-319-21956-1 (33 pages, 8 figures
From one to many: Simulating groups of agents with reinforcement learning controllers

Simulation of crowd behavior has been approached through  many different methodologies, but the problem of mimicking human decisions and reactions remains a challenge for all. We propose an alternative model for simulation of pedestrian movements using Reinforcement Learning. Taking the approach of microscopic models, we train an agent to move towards a goal while avoiding obstacles. Once one agent has learned, its knowledge is transferred to the rest of the members of the group by sharing the resulting Q-Table. This results in individual behavior leading to emergent group behavior. We present a framework with states, actions and reward functions general enough to easily adapt to different environment configurations.Peer ReviewedPostprint (author’s final draft
Narrative Variations in a Virtual Storyteller

Research on storytelling over the last 100 years has distinguished at least
two levels of narrative representation (1) story, or fabula; and (2) discourse,
or sujhet. We use this distinction to create Fabula Tales, a computational
framework for a virtual storyteller that can tell the same story in different
ways through the implementation of general narratological variations, such as
varying direct vs. indirect speech, character voice (style), point of view, and
focalization. A strength of our computational framework is that it is based on
very general methods for re-using existing story content, either from fables or
from personal narratives collected from blogs. We first explain how a simple
annotation tool allows naive annotators to easily create a deep representation
of fabula called a story intention graph, and show how we use this
representation to generate story tellings automatically. Then we present
results of two studies testing our narratological parameters, and showing that
different tellings affect the reader's perception of the story and characters.Comment: Intelligent Virtual Agents (IVA 2015
Offscreen and in the chair next to your: conversational agents speaking through actual human bodies

his paper demonstrates how to interact with a conversational agent that speaks through an actual human body face-to-face and in person (i.e., offscreen). This is made possible by the cyranoid method: a technique involving a human person speech shadowing for a remote third-party (i.e., receiving their words via a covert audio-relay apparatus and repeating them aloud in real-time). When a person shadows for an artificial conversational agent source, we call the resulting hybrid an “echoborg.” We report a study in which people encountered conversational agents either through a human shadower face-to-face or via a text interface under conditions where they assumed their interlocutor to be an actual person. Our results show that the perception of a conversational agent is dramatically altered when the agent is voiced by an actual, tangible person. We discuss the potential implications this methodology has for the development of conversational agents and general person perception research
Creating and evaluating embodied interactive experiences: case studies of full-body, sonic and tactile enaction.

This thesis contributes to the field of embodied and multimodal interaction by presenting the development of different original interactive systems. Using a constructive approach, a variety of real-time user interaction situations were designed and tested, two cases of human-virtual character bodily interaction, two interactive sonifications of trampoline jumping, collaborative interaction in mobile music performance and tangible and tactile interaction with virtual sounds.
While diverse in terms of application, all the explored interaction techniques belong to the context of augmentation and are grounded in the theory of embodiment and strategies for natural human-computer interaction (HCI). The cases have been contextualized within the umbrella of enaction, a paradigm of cognitive science that addresses the user as an embodied agent situated in an environment and coupled to it through sensorimotor activity. This activity of sensing and action is studied through different modalities: auditory, tactile and visual and combinations of these. The designed applications aim at a natural interaction with the system, being full-body, tangible and spatially aware. Particularly sonic interaction has been explored in the context of music creation, sports and auditory display. These technology-mediated scenarios are evaluated in order to understand what the adopted interaction techniques can bring to the user experience, how they modify impressions and enjoyment. The publications also discuss the enabling technologies used for the development, including motion tracking and programmed hardware for the tactile-sonic interaction and sonic and tangible interaction.
Results show that combining full-body interaction with auditory augmentation and sonic interaction can modify the perception, observed behavior and emotion during the experience. Using spatial interaction together with tangible interaction or tactile feedback provides for a multimodal experience of exploring a mixed reality environment where audio can be accessed and manipulated with natural interaction. Embodied and spatial interaction brings playfulness to a mobile music improvisation, shifting the focus of the experience from music-making towards movement-based gaming. Finally, two novel implementations of full-body interaction based on the enactive paradigm are presented. In these designed scenarios of enaction the participant is motion tracked and a virtual character rendered as a stick figure is displayed in front of her on a screen. Results from the user studies show how the involvement of the body is crucial in understanding the behavior of a virtual character or a digital representation of the self in a gaming scenario