9:00 - Opening
9:10 - José Ademir S. de Lima
9:35 - Bruno Mota
10:00 - Luca Amendola
10:25 - coffee break + posters
11:00 - Joshua Frieman
11:25 - Ribamar Reis
11:50 - Sérgio Jorás
12:15 - Martin Makler
12:40 - ***Lunch***
14:10 - Miguel Quartin
14:35 - Raul Abramo
15:00 - Rogério Rosenfeld
15:25 - Valerio Marra
15:50 - coffee break + posters
16:25 - Vivian Miranda
16:50 - Marcelo Vargas
17:15 - Mauricio Calvão
17:40 - Closing - Ioav Waga
José Ademir S. de Lima
Title: Cosmic Concordance Versus Gravitationally
Induced Matter Creation Models
Abstract: We show that a cosmology driven by
gravitationally induced particle production of all
non-relativistic species existing in the present Universe
mimics exactly the observed flat accelerating LCDM
cosmology with just one dynamical free parameter. The new
cosmic scenario is equivalent to LCDM both at the
background and perturbative levels and the associated
creation process is also in agreement with the
universality of the gravitational interaction.
Implicitly, it also suggests that the present day
astronomical observations cannot be considered the
ultimate proof of cosmic vacuum effects in the evolved
Universe because LCDM may be only an effective cosmology.
Bruno Mota pdf
Title: Effective search strategies for cosmic topology in
CMB maps
Abstract: It has become clear in recent years that we
live in an Universe with spatial sections that are either
flat or very nearly flat. The topology of these spatial
sections is not specified by any known fundamental theory,
but the set of potential non-simply connected manifolds is
very different for different signs of the gaussian
curvature. Observationally, each such manifold would
produce a different pattern of repeat images of distant
cosmic objects; in CMB maps these would take the form
of pairs of circles with identical patterns of
temperature anysitropies. Searches for these so-called
circles-in-the-sky, however, are computationally intensive
and subject to masking effects, and have been so far
unsuccessful. Here I show how observational constraints on
the curvature and the careful enumeration of candidate
manifolds can radically reduce the parameter space search
volume, and modestly increase detection sensibility.
Luca Amendola pdf
Title: Fundamental physics with the Euclid satellite
Abstract: TBD
Joshua Frieman pdf
Title: Ioav's Universe
Abstract: TBD
Ribamar Reis pdf
Title: Studying supernovae with narrow band filters
Abstract: TBD
Sérgio Jorás pdf
Title: Modified Theories of Gravity
Abstract: TBD
Martin Makler pdf
Title: Hopes in the Dark
Abstract: Two decades ago, the discovery of the current
accelerated expansion of the Universe boosted a new field
in cosmology: Dark Energy (DE). An enormous theoretical
and observational effort has been undertaken since then to
shed light on this unknown component. On the one hand,
physical models were attempted to describe DE, both from
fundamental physics and on phenomenological grounds. In
this later category, an appealing approach tried to unify
DE with the other unknown component of the Universe: the
Quartessence scenario was born. We proposed Quartessence
models and confronted them to the available data,
essentially discarding the hope for a simple Dark Matter
and Dark Energy unification. On the observational front,
several experiments were specifically designed to probe
DE, among which, the Dark Energy Survey (DES), for which
we have carried out a number of studies aiming at Strong
Lensing (SL) and the derived constraints on DE from this
observable. In fact, SL may provide unique information on
the dark content of the Universe. We show one example
using recent data on a Strong Lensing cluster. In this
presentation I will briefly navigate through the aspects
above, pointing out some known and some probably unknown
contributions form Ioav during my journey across them.
Miguel Quartin pdf
Title: 1-point lensing statistics in cosmology
Abstract: Lensing in cosmology is usually discussed in
terms of the Cosmic Shear, a 2-point correlation
statistic. The lensing probability distribution functions
(PDF) of convergence, shear and magnification, on the
other hand, carry extra information
which can be recovered in a different way. I will discuss
some challenges in extracting this signal, which requires
an accurate modelling of the cosmological dependence of
the PDFs. I will focus on the effect of baryons, computed
using the Magneticum suite of simulations, which have a
significant impact on the high magnification and high
convergence regions of the PDFs. I will also discuss how
the angular resolution of the observations must be taken
into account when modelling the PDFs.
Raul Abramo pdf
Title: Dark down South
Abstract: The story of brazilian research in the dark
sector of cosmology cannot be told without Ioav Waga. I
wil tell part of that story: how we created new areas,
beyond purely theoretical research, thanks in large part
to Ioav's good taste, his ability to make friends across
continents and cultures, and his long-term view of the
game.
Rogério Rosenfeld pdf
Title: New Physics in Space: the growth of a community
Abstract: I present some thoughts about the changes in
our community in the past years.
Valerio Marra pdf
Title: No fundamental acceleration scale in disk galaxies
Abstract: The Radial Acceleration Relation confirms that
a nontrivial acceleration scale can be found in the
average internal dynamics of galaxies. The existence of
such a scale is not obvious as far as the standard
cosmological model is concerned, and it has been
interpreted as a possible sign of modified gravity. The
implications could be profound: it could in principle
explain galactic dynamics without large amounts of
yet-undetected dark matter and address issues that the
standard cosmological model faces at galactic scales.
Here, we consider 193 disk galaxies from the SPARC and
THINGS databases and, using Bayesian inference, we show
that the probability of existence of a fundamental
acceleration that is common to all the galaxies is
essentially zero: the null hypothesis is rejected at more
than 10 sigma. We conclude that the acceleration scale
unveiled by the Radial Acceleration Relation is of
emergent nature, possibly caused by a complex interplay
between baryons and dark matter. In particular, the MOND
theory, or any other theory that behaves like it at
galactic scales, is ruled out as a fundamental theory for
galaxies at more than 10 sigma.
Vivian Miranda pdf
Title: Probing Inflation, Reionization and Cosmic
Acceleration with Cosmological data
Abstract: The standard paradigm of cosmology is built
upon on a series of premises on how the early,
intermediate and late-time universe behaves, and the
current data is already powerful enough to exam some of
the hypotheses behind the standard model. In this talk, I
propose a program to investigate how we can falsify these
hypotheses with space missions in the 2020s in combination
with ground-based observatories. One unique aspect of this
proposal is that I will properly account for systematic
effects as well as theoretical uncertainties (e.g.,
modeling inflation and reionization through CMB data).
This program will be crucial to set the strategy for the
WFIRST Type Ia supernova and weak lensing surveys. The
WFIRST satellite is scheduled to launch in 2024-25; the
complete observational plan needs to be ready soon to set
the requirements for instrumentation. I will lead the
analysis on how Type IA supernova and weak lensing can be
combined to test paradigms of cosmic acceleration, and how
different strategies can affect this goal. In addition to
research on the WFIRST mission, my short-term
investigations on how inflation and reionization affect
CMB inferences on dark energy will provide long-term
guidance to NASA on how future CMB satellite missions can
be used to test some of the core hypotheses of the
standard model.
Marcelo Vargas pdf
Title: Supernova classification by decision tree
ensembles and automated machine learning
Abstract: The efficient classification of the different
types of Supernova is one of the most important problems
of the observational cosmology but a spectroscopic
confirmation of type for all supernova observed by the
current and upcoming photometric surveys, such as the Dark
Energy Survey (DES) and the Large Synoptic Survey
Telescope (LSST), will be impossible therefore the
development of automated classification process based on
photometry has become a great challenge. In this work we
revisit the Supernova Photometric Classification Challenge
(SPCC) by two different approaches: (I) A multi-faceted
classification pipeline covering a range of representative
machine learning based on decision trees algorithms:
AdaBoost (ADA), Random Forests (RF), Extra Tree
Classifiers (EXT), Gradiend Boost (GB) and Extreme
Gradient Boost (XGB); (II) A automated search process to
find the best machine learning pipeline. To perform this
search we use the TPOT library
(epistasislab.github.io/tpot), built on top of
scikit-learn, the TPOT perform an intelligent exploring
thousand of possible pipelines to find the best one for
the training set using the genetic programming
implementation from the DEAP library
(deap.readthedocs.io). In both cases, we use four sets of
features: A template fitting, the SALT2 model, two
different parametric models for the light curve shape
(Newling and Karpenka), and wavelets decomposition. We
also test the how these models behave when we vary the
training set size and include the host galaxy redshift
($z_{host}$) as a feature, we compute two different
metrics to compare both approaches: (i) the area under the
curve (AUC) of the Receiver Operating Characteristic; (ii)
The average precision.
Mauricio Calvão pdf
Title: Kinematics of frames in arbitrary spacetimes
Abstract: We will present two kinds of results related to the kinematics of reference frames in arbitrary spacetimes: (1) the characterization and (non-)existence of inertial frames, and (2) the (non-)existence of geodesic nonexpanding frames in Robertson-Walker spacetimes
Title: Spherical collapse with dark energy perturbations
Abstract: The influence of dark energy on the formation
of structures is currently one ofthe major problems in
Cosmology, since it can distinguish otherwise degenerated
models. Inthis work we consider the Spherical-Collapse
model with dark energy, which can partially (ortotally)
cluster, according to a free parameter. The energy
conservation has to be taken intoaccount accordingly, as
we will show. We determine characteristic quantities for
this model,such as critical contrast density, radius
evolution, virial radius, virialization overdensity
andnumber of clusters (using the Sheth-Tormen mass
function), with particular emphasis on theirdependence on
the clustering parameter. We show that the virialization
overdensity does notdiscriminate between such models.