"The Cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the Cosmos stir us — there is a tingling in the spine, a catch in the voice, a faint sensation as if a distant memory, of falling from a height. We know we are approaching the greatest of mysteries".

Carl Sagan, Cosmos (1980).

(This page is outdated.)
The Supernova Project:
Machine learning techniques for classifying rare astrophysical events.

X-Ray Busters and their constraints to the Neutron Star Mass-Radius Relation and the Equation of State of Dense Matter

New!!! A comprehensive review about the Physics of X-ray Bursters!.

A set of modules to process, parse and analyze the data from X-ray atmosphere simulations.

Understand the the opacity in the atmosphere of astrophysical sources (neutron stars).

The first atmosphere results from our code!

I wrote a brief review on X-ray bursters.

The reproduction of fits from Suleimanov's (2010) paper, using their sets of data can be seen here. Source code here.

A short tutorial on how to submit jobs on on the New York Blue at Brookhaven National Laboratory.

Publications

On Classifying Complex Networks by their Topological Features (in review).

Sub-Eddigton Model Atmospheres, Spectra, and Color Corrections for X-Ray Bursting Neutron Stars (in review).

Sub-Eddigton Model for Low-Temperature X-Ray Bursting Neutron Stars (in review).

Jet-Underlying Event Separation Method for Heavy Ion Collisions (Phys. Rev. C 86, 024908 2012).

Past Research

Poisson Structure on Moduli of Flat Connections on Riemann Surfaces. Under supervision of Dr. Nikita Nekrasov (2012).
We studied the space of graph connections (lattice gauge fields) endowed with a Poisson structure , based on previous work from V.V.Fock and A.A.Rosly. We applied this Poisson structure on the moduli space of locally flat vector bundles on a Riemann surface with holes, for instance a sphere with four holes (i.e boundaries), common structure in string theory .

Jets Studies in the Quark-Gluon Plasma. Under supervision of Dr. Barbara Jacak (2012).
Studies performed with my collaborators at PHENIX, in the Brookhaven National Laboratory, PRC 86, 024908 (2012).
We reconstructed jets in heavy ion collisions, with an original method to separate these jets from the underlying, particularly in central heavy ion reactions, utilizing the HIJING and PYTHIA event generators. This method, extended from previous work by the ATLAS collaboration, provides a well-defined association of "truth jets" from the fragmentation of hard partons with "reconstructed jets".

Qubits with Coupled Squids. Under supervision of Dr. Dima Averin (2011).
We studied the eigenfunctions of many coupled SQUIDs (superconducting quantum interference device)together, and the possibility of generating some of the quantum gates that are necessary for quantum information. There are many advantage of using SQUIDs (which are based on superconducting loops containing Josephson junctions) as two-state systems in quantum computing problems, mainly due its very sensitive magnetometer, capable of measuring extremely subtle magnetic fields.

Equations of State for Dark Matter and Dark Energy as Decaying Interacting Fluids. Under supervision of Dr. Elcio Abdalla (2008).
We studied the existence of a positive cosmological constant on the Einstein Equations, and its relation to the De Sitter Space in Quantum Field Theory. We suppose an interaction between Dark Matter and Dark Energy, investigating the influence of this interaction upon the dynamics of galaxy Clusters and observational constraints from cosmological parameters. The dynamical equilibrium of collapsed structures is affected by the coupling of Dark Energy and Dark Matter, with a similar effect when the equivalence principle is violated in the dark sector. We suggest that the virial theorem is distorted by a non-conservation of mass caused by the coupling, with the Layser-Irvine Equation. A report of the project can be seen here (in Portuguese).

(This page is outdated.)
My projects in Physics and Computer Science, including several notes and e-books I have written during grad school!
I have been receiving nice feedback for my ebooks about Group Theory and on Algorithms in Python (available below). Thank you everyone!

Machine Learning and Data Mining

Machine Learning (2014)
Material from the graduate course at Stony Brook University. The source code for the homework is here, with many algorithms in Python/NumPy comparing Naive-Bayes vs. Logistic Regression, performing Adaboost, and comparing kNN vs. SVM. My theoretical homeworks, from the entire course, is here.

Classifying Complex Networks (2014)
This project is divided in three parts. The code to extract the publicly available databases and to calculate the topological features for the graph databases is here. The code to cleanse and organize the data is here. The code to perform the machine learning for many (supervised and unsupervised) methods is here. All the results and plots are available here. A talk about the project is here. The first draft of the paper is here.

Information Diffusion in Twitter (2011)
A very introductory essay about graphs and information diffusion in social network, under supervision of Prof. K. Mueller. Simple examples of high-dimensional space parameterizing each tweet to capture the information diffusion and graph layout.

A Crash Course on Basic Statistics (2011)
A very brief review on basics on statistics and probability.

Algorithms and Computational Puzzles

Algorithms & Python (2013) (e-book)
A comprehensive study on Algorithms, Data Strucutres & and Python, for my own amusement. The notes can be found here.
Over 100 examples are available in the repository.

Numerical Methods (2013)
Code and homework for the graduate class taught by Prof. M. Zingale at Stony Brook University (the codes are here):

Integration and Differentiation: numerical derivatives, error estimates, Simpson's rule.
Ordinary Differential Equations: Euler and Euler-Cromer methods, Verlet method.
Linear Algebra and FFTs: time series for the damped driven pendulum, matrix inverse, conditional number.
Advection and Hyperbolic Partial Differential Equations: implicit advection, Lax Wendroff, non-linear hyperbolic equations.
Elliptic Partial Differential Equations.
Computational Fluid Dynamics: Rayleigh-Taylor Instabilities.

Computer Vision and Graphics

Robotics (2013)
Homework and studies for Prof. A.Berg's class in introduction to robotics (Stony Brook University):

Computational Photography (2013)
Homework and studies for Prof. T. Berg's class in computational photography (Stony Brook University):

Gradient-domain Fusion of Pictures.
Face Morphism.
Automatic Colorization of Greyscale Faces.
On Depth Sensors Applications for Computational Photography and Vision: A short white-paper about how to get started with Kinect in Linux .

3D Modeling and 3D Printing with Google SketchUp (2013)
Many examples of 3D model of objects tutored by Phil Webster in the Simons Center for Geometry and Physics.

Astrophysics

Non-Linear Least Square Fit applied to the X-Ray Problem (2012)
Five ways of performing a non-linear least square fit for simulations of X-ray bursters atmospheres, here.
A brief review on X- ray bursters can be seen here.

The Ledoux Criterion for Convection in a Star (2012)

Observational Astronomy (2012)
Calibration, combination, and analysis of astrophysical images for photometry and spectroscopy. These are results from the graduate class taught by Prof. Stan Metchev:

On the Spectroscopy Study of the Earthshine Spectra: report and source code.
On the Calculation of the Angular Diameter of the Sun by Milchelson Radio Interferometer: report.
On the Measurement of Stellar Fluxes on the Interstellar Dust Extinction of M35: report and source code.

Computer Security

MonCSRF: CSRF defenses for Apache + ModSecurity (2011)
This was a final project for the graduate Computer Security class, taught by Prof. Sekar:

A tool to monitor web server's log files against CSRF attacks.

It is a nice example of parser in Ruby and Ragel, together with some examples in C++ and Python.

Some examples of modifications for modsecurity on Apache (used in examples in the program).

Over 50 solved exercises on basic concpets on computer security and attacks.

THEORETICAL AND PHENOMENOLOGICAL PHYSICS

$Scattering, Diffraction and Radiatiom.$

Group Theory for Physicists (2010) (e-book)
This is a 110-pages review I wrote in my first summer of PhD. It is based on classes, homework and readings and there are lots of solved exercises!

Introduction to Quantum Field Theory and Colliders(2010) (e-book)
This is a 120-pages review I wrote in my first year of PhD based on classes, homework, and readings.

Searching for Dark Matter(2010)
Very short presented for Quantum Field Theory II class, with Prof. George Sterman.

The Maxwell-Chern-Simons Theory (2010) and Field Theory on Photoproduction (2010)
Very short papers presented for the Elementary Particle class, with Prof. Dima Kharzeev.

The SU(5) Group as a GUT (2010)
Very short paper for this nice example of gauge theory.

Colliders (2010)
An undergrad review on how a collider works.

New Physics at LHC (2010)
Another undergrad review of some nice things expected at LHC that time.

The Cosmological Constant (2007) (e-book)
An undergrad review on general relativity and cosmology (in Portuguese).

The Standard Model (2007)
An undergrad review on the standard model (in Portuguese).

Topological Quantum Field Theories (2011)
Notes I took during Prof. Sasha Kirillov's graduate class.

On the study of the Potts model, Tutte and Chromatic Polynomials (2012)
Paper presented for the Statistic Mechanics Class, with Prof. Robert Shrock.

Introduction to Quantum Computing (2010) (e-book)
A (very) incomplete 140-pages review on quantum mechanics and quantum computing. Several solved exercises on quantum mechanics.

Superconductivity (2010) and Scattering, Diffraction and Radiation (2010)
Two short papers with exercises from Electromagnetism II, with Prof. Zahed.

The DGLAP Equations (2011)
Short paper presented for the Elementary Particle class, with Prof. Dima Kharzeev.