Current developments in deep learning suggest that multi-layered architecture are especially efficient to encode information and perform decision. Many pathways in biology display similar structure: for instance the drosophila segmentation pathway is organized in 4 feed forward layers of maternal, gap, pair-rule and segment polarity genes. The goal of the project will be to study the theoretical connections between biological networks and deep architecture, following up on current research performed in the Francois group. More precisely, the student will use a machine learning approach developed in the group to reverse engineer a developmental network from data, then to compare them to actual networks existing in nature.

The student will learn and use standard machine learning tools to design an algorithm learning from data (both synthetic and shared by our collaborators). He/she will have daily meetings with the supervisor, as well as regular interactions with all members of the group.

For more information contact: Paul François (paulf at physics dot mcgill dot ca).

Posted on 2018/01/09

The ATLAS experiment at the CERN's Large Hadron Collider in Geneva records the results of the highest energy particle collisions ever produced in laboratory. In 2012, the ATLAS and CMS collaboration announced the discovery of a new elementary particle of nature, the so-called Higgs boson. In order to more precisely study the properties of this new particle, test the validity of the Standard Model of particle physics and further extend the search for new physics phenomena, the ATLAS detector will be undergoing a major upgrade in 2019. Canada is constructing approximately one third of the specialized detectors required for this upgrade. The McGill group is responsible for the testing and characterization of these Canadian-made chambers. The production of these "thin gap chambers" has begun in Summer 2017. The goal of this summer research project is to participate in the testing and characterization of Canadian-made "thin gap chambers" for the upgrade of the ATLAS experiment. The student will learn about different particle detection techniques and develop a wide range of experimental skills.

The student will be asked to participate in the data taking of cosmic ray data with the new Canadian-made detector. Depending on the status of the project by summer 2018, the student?s tasks will include some of the following: help in the development of the laboratory infrastructure, participation in the analysis of cosmic data and/or simulation studies associated with the optimization of the detector testing, development of the testing work flow and associated documentation, and testing of readout electronics components.

For more information contact: Brigitte Vachon (vachon at physics dot mcgill dot ca).

Posted on 2018/01/09

The ATLAS experiment at the CERN's Large Hadron Collider (LHC) in Geneva records the results of the highest energy particle collisions ever produced in laboratory. The LHC is scheduled to undergoe a major upgrade in 2025 that will result in an increase of its beam intensity by nearly an order of magnitude. In order to cope with this new extreme environmental conditions, the ATLAS detector will undergoe a major upgrade of several of its subsystem. One of this upgrade consist in replacing the entire readout electronics of the Liquid Argon Calorimeter detector, a sub-system responsible for precisely measuring the energy of electrons/photons produced in proton-proton collisions. The goal of this summer research project is to participate in the ongoing R&D to define the exact design and technology of the future readout electronics (which includes both an analogue and a digital part). The student will learn about different concepts of analogue and digital electronics and develop FPGA programming skills.

The student will help design a prototype digital readout system based on a commercial FPGA (Field Programmable Gate Array) development kit and test some of its performance. Depending on the project timeline, tests of the prototype digital readout may be possible at the TRIUMF laboratory. The student may also be required to participate in some simulation studies for the optimization of different possible parameters of the readout chain.

For more information contact: Brigitte Vachon (vachon at physics dot mcgill dot ca).

Posted on 2017/02/21

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a radio telescope currently being built in Penticton, BC, funded by the Canada Foundation for Innovation (CFI). CHIME was designed for sensitive observations of hydrogen in the distant galaxy for cosmological purposes. However CHIME can also be used as a detector of Fast Radio Bursts (FRBs), a new and mysterious astrophysical phenomenon in which short (few ms) radio bursts appear randomly in the sky. FRBs are thought to be extragalactic due to their dispersion measures that are far higher than the maximum amount available in our Milky Way. With FRB event rates of ~1000 /sky/day, they raise an interesting puzzle regarding their origin, which may like at cosmological distances. CHIME's great sensitivity and large field-of-view (250 sq deg) will enable the detection of tens of FRBs per day — in contrast to the fewer than 2 dozen discovered since 2007. For this reason, we have been granted additional CFI funding to build a real time FRB detector back-end instrument for CHIME. We expect first light for CHIME and our FRB back end in late 2017. The proposed research project is to assist the McGill group, in collaboration with colleagues at U. Toronto, UBC and elsewhere, in the design and implementation of algorithms and software for the FRB back-end instrument for CHIME. The project will involve becoming familiar with the hallmark signatures of FRBs and with the planned software pipeline, and contributing to the software development either by testing out new algorithms or implementing ones already tested. Observations of pulsars with the existing CHIME pathfinder may also be possible.

The student, who should have experience and familiarity with programming in the Linux environment, will be given astrophysical data sets from CHIME or other radio telescopes (possibly including Arecibo and the Green Bank Telescopes) to first familiarize themselves with source properties. Then, depending on exact interest, may help develop and test new algorithms for distinguishing such signals from Terrestrial interfence, or may help develop a database of source properties for eventual use with CHIME. One other option is to help develop a real time alert system for informing the worldwide astrophysical community of CHIME events to enable multiwavelength follow-up.

For more information contact: Victoria Kaspi (vkaspi at physics dot mcgill dot ca).

Posted on 2018/01/10

Interfacing bio materials, such as neurons with optical and electronic devices is important for many applications, including health technologies. Using the unique properties of graphene, such as its strength, flexibility, bio-compatibility, high transparency and high mobility makes it an ideal interface material. Graphene is an atomically thin two dimensional carbon based material and the goal of this project is to synthesize graphene using chemical vapor deposition in three dimensional shapes. This project builds on our group's expertise to synthesize graphene in various geometries such as needles that can be used as implants for neurons.

The student will learn to synthesize high quality graphene, to fabricate three-dimensional graphene structures and to study their interface properties with bio-materials such as neurons. The student will interact daily with other members of the group and will have weekly meetings with the supervisor.

For more information contact: Michael Hilke (hilke at physics dot mcgill dot ca).

Posted on 2018/01/15

My group is part of the HELIX (High-Energy Light Isotope eXperiment) collaboration. We are preparing a balloon-borne detector that will be flown from the coast of Antarctica during the 2019-20 austral summer. The detector will spend 14 days circumnavigating the continent at an altitude of 45 km. The aim is to measure the relative fluxes of stable Be-9 and its radioactive counterpart Be-10 in the cosmic radiation. This will allow tests of models of the local galactic environment and is motivated by the anomalous flux of energetic positrons in the cosmic rays.

A key component of the HELIX payload is a ring-imaging Cherenkov detector (RICH) which is needed to identify the different Be isotopes. The RICH makes use of silica aerogel with refractive index of approximately 1.15. To achieve the necessary accuracy we need to measure this number with a precision of 0.1% on a grid with 5 mm pitch over the face of 60 100mm-by-100mm tiles. We are developing tools to make these measurements in my lab at McGill and will take them to the National Research Council in Ottawa in August. There we will use a 35 MeV electron beam to generate the Cherenkov radiation needed for the calibration.

The summer-student will assist with the instrument development and help with the beam tests. S/he will develop analysis code and calibration protocols as well as the related documentation.

Weekly meetings with the supervisor and daily interactions with other members of the McGill HELIX group will keep the research on track. A written report will be submitted at the end of the summer.

Experience with electronics and knowledge of Python and/or C++ is an asset but not a requirement.

For more information contact: David Hanna (hanna at physics dot mcgill dot ca).

Posted on 2018/01/15

Fluorescence Cross-Correlation Spectroscopy (FCCS) is the study of the fluctuations and kinetics of interacting molecules; and in many experimental implementations, the background fluorescence presents a significant source of noise. A wide-field implementation of FCCS, using confinement microscopy, can dramatically improve background suppression, and extend observation times, enabling new measurements of weak and slow DNA-DNA, protein-DNA and protein-protein interactions under unprecedented conditions.

In this summer project, the student will apply and further develop FCCS image analysis tools, to analyze fluorescence images of freely diffusing and interacting molecules, at micromolar reagent concentrations and over several-minutes-long timescales. By comparing results to theoretical models, the student will extract meaningful system parameters, such as concentration, binding and unbinding rates, and diffusivity, as a function of the applied confinement.

The student will receive training in microscopy (optics, experiment design, device control) and quantitative data analysis (Matlab) as well as theory, and work closely with a graduate student on this project. Weekly meetings with the supervisor and collaborators, and daily interactions with members of the research group, will support and guide the project. Anticipated outcomes of the summer research project include publication in an international peer-reviewed journal and presentations at local conferences and workshops in the fall, providing the student with key training in writing and oral communication.

For more information contact: Sabrina Leslie (sleslie at physics dot mcgill dot ca).

Posted on 2018/01/24

The varied surfaces and atmospheres of planets make them interesting places to live, explore, and study from afar. Unfortunately, the great distance to even the closest exoplanets makes it impossible to resolve their disk with current or near-term technology. It is still possible, however, to deduce spatial inhomogeneities in exoplanets provided that different regions are visible at different times. In the past decade, we have been able to construct thermal maps and reflectance maps of short-period giant planets using the Spitzer and Kepler space telescopes, respectively. Future instruments should enable exo-cartography of smaller and/or cooler planets.

The student will master and modify existing Python code for mapping planets in reflected light based on disk-integrated photometry. They will use this code to construct albedo maps of short-period planets using data from Kepler, and/or test the impact of instrument noise and cadence on the quality of inferred maps, in order to the inform the design of experiment for next-generation instruments. Depending on interest, they can implement modules to account for non-diffuse reflection or time-variable clouds.

For more information contact: Nicolas Cowan (cowan at physics dot mcgill dot ca).

Posted on 2018/01/25

DNA-DNA and protein-DNA interactions are crucial to cellular processes, with errors in these reactions sometimes leading to genetic diseases such as cancer. Emerging single-molecule microscopy techniques allow for multiple, independent interactions to be imaged at once - in order to access both the expected behaviour, as well as deviations from the norm. Imagery of single molecules, however, is typically limited in signal-to-background; this presents an opportunity to develop computer-vision algorithms to extract salient information about the molecules.

For this project, the student will develop an analysis software package in order to study the interactions between labelled probe molecules and unwinding sites on supercoiled DNA which are trapped in large nanowell arrays. Statistical mechanics theory predicts the probability for a specific DNA molecule commonly used in biology for cloning to unwind at two possible sites under different experimental conditions. As background to this project, PhD students have collected fluorescence images of mixtures of DNA molecules and probe molecules (oligonucleotides, proteins). This computational project focuses on implementing computer vision and principal component analysis (PCA) algorithms to improve measurements of binding kinetic rates and stoichiometries, and on running simulations to test the analysis methods.

The student will receive training in quantitative data analysis (Matlab) as well as theory, and work closely with a graduate student on this project. Weekly meetings with the supervisor and collaborators, and daily interactions with members of the research group, will support and guide the project. Anticipated outcomes of the summer research project include presentations at local conferences and workshops in the fall, providing the student with key training in writing and oral communication.

For more information contact: Sabrina Leslie (sleslie at physics dot mcgill dot ca).

Posted on 2018/01/26

In this collaborative project between the Reisner and Grutter groups, the USRA student will help develop a new technique for making precisely positioned sub 5 nm nanopores. The successful demonstration of nanopore sequencing via engineered protein pores has created considerable industrial interest in nanopore based technologies. The next research frontier in nanopore physics is the development of solid-state nanopore devices, which admit of more scalable fabrication processes and will potentially have higher resolution, decreasing the high sequencing error-rates that are currently the main drawback in nanopore sequencing. We have developed a new approach for fabrication of sub 5 nm pores via local dielectric breakdown induced by a conductive AFM tip across a ~10nm nitride membrane. In our approach, a conductive AFM tip is brought into contact with a nitride membrane sitting on top of an electrolyte reservoir. Application of a voltage pulse leads within seconds to formation of a nanoscale pore that can be detected by a subsequent AFM scan. This approach combines the ease of classic dielectric breakdown with the nanoscale pore positioning capability of high energy particle milling techniques such as TEM and FIB. The student will learn to create pores in nitride membranes using an AFM setup in the Grutter group and then will perform DNA translocation measurements in the Reisner group with the pores. The student will meet on a weekly basis with supervisors Prof. Reisner and Grutter.

For more information contact: Walter Reisner (reisner at physics dot mcgill dot ca).

Posted on 2018/01/26

The use of convolutional neural networks is gaining momentum in the field of bioimaging, and the current challenges present themselves in the areas of cell tracking and segmentation. Most of the applications to date have involved analysis of cell and tissue images acquired with light sheet or confocal microscopy, for which the spatial resolution is limited by the light diffraction limit. This project will be focused on using deep learning for image processing and segmentation analysis of subcellular structures of various yeast mutants. In order to investigate and segment the components of the cellular environment at this sub-diffraction limit, the imaging data will be acquired with super-resolution stimulated emission depletion (STED) microscopy. Segmentation analysis will be performed with the goal of using machine learning to automate phenotyping of various mutant yeast cell lines based on the orientation and distribution of microtubules during the various stages of the cell cycle.

The student will acquire knowledge in the field of deep learning, experimental biophysics, confocal fluorescence and super-resolution STED microscopy. The student will be directly supervised by the PI and receive in lab training from a graduate student.

For more information contact: Paul Wiseman (wiseman at physics dot mcgill dot ca).

Posted on 2018/01/29

The EXO (Enriched Xenon Observatory) collaboration is searching for lepton-number violating neutrino-less double beta decays (0νββ) in Xe-136. A positive observation would require the neutrino to be its own anti-particle, i.e. the neutrino has to be a Majorana particle, and shed light on various open questions in neutrino physics. The current limit on the 0νββ half life in Xe-136 measured by the EXO-200 collaboration is T_1/2>1.8 × 10²⁵ years. New technologies are being developed to further increase the sensitivity of the next generation detector. One of those is the so-called Ba-tagging technique. Here, the Xe-decay daughter Ba-136 is located inside the detector volume after the decay, extracted from the volume and identified. This Ba-tagging technique will allow the unambiguous identification of �� decays by clearly distinguishing them from background events. This technique will be particularly important to verify an observation once a positive 0νββ signal has been observed.

A Ba-tagging technique is being developed at McGill with the focus on the extraction and identification of Ba-ions from xenon gas. For systematic studies and to determine the efficiency of the identification process we require a single Ba-ion source. The summer projects focuses on the optimization and characterization of a laser-driven single Ba-ion source. A pulsed laser beam is focused on a surface with a known elemental composition where it ablates atoms and ions. Ions are guided away from the surface by electrostatic lenses and injected into the ion identification setup. These well-known ions are used to calibrate the identification setup and determine transport efficiencies throughout the system.

You will be embedded in the local nEXO group at McGill and learn about neutrino physics and ion manipulation techniques. Ion optics geometry and ion transport will be simulated and optimized using the SimIon software. Based on these simulations, initial ion-ablation tests will be performed and ion production will be optimized.

This project is aimed at undergraduate students at all levels, i.e., no special skills, apart from a general understanding of physics, are required. All you need is an interest in learning and improving lab skills, and an interest in particle and nuclear physics. We use SolidWorks, LabView, Mathematica, and Python in every-day-business. Some knowledge in any of these programs/languages will help you get started, but is absolutely not required as we have local experts that are happy to assist you.

For more information contact: Thomas Brunner (brunner at physics dot mcgill dot ca).

Posted on 2018/02/05

The EXO (Enriched Xenon Observatory) collaboration is searching for lepton-number violating neutrino-less double beta decays (0νββ) in Xe-136. A positive observation would require the neutrino to be its own anti-particle, i.e. the neutrino has to be a Majorana particle, and shed light on various open questions in neutrino physics. The current limit on the 0νββ half life in Xe-136 measured by the EXO-200 collaboration is T_1/2>1.8 × 10²⁵ years. New technologies are being developed to further increase the sensitivity of the next generation detector. One of these technologies are silicon photomultipliers (SiPMs). The collaboration is working on developing these devices sensitive to Xe-scintillation light at 175nm. Special light sources are required to actually produce photons of this wave length.

In this summer research project, an electroluminescent light source is being developed for SiPM testing. Photo-electrons are created at an Ag cathode and then drifted through xenon gas where they cause the emission of electroluminescent photons at 175 nm. This is the same wavelength that will be detected by the SiPM photon sensors in nEXO. The electric drift field of the light source and the operation parameters have to be chosen as such that short pulses on the order of 100ns are emitted by the source. A prototype of such an electroluminescent light source has been fabricated and will be tested this summer.

You will join the local EXO group at McGill and learn about neutrino physics and detection techniques using liquid Xe. You will be working on the development of photon sensors as part of an international team of researchers. Your project will be well defined with achievable goals. You will perform every day lab work, and most studies and experiments within a small team of undergraduate and graduate students in our lab at McGill. Senior scientists at McGill and within the nEXO collaboration are happy to help you get started and will help you conduct your measurements.

For more information contact: Thomas Brunner (brunner at physics dot mcgill dot ca).

Posted on 2018/02/05

A THz pulse is a phase-stable, single cycle pulse of light with bandwidth lying in the 0.1 - 10 THz region of the electromagnetic spectrum. Through advanced nonlinear optical methods, it is now possible to generate intense THz pulses with peak electric fields on the order of MV/cm. These intense fields can be used to drive highly nonlinear phenomena, such as ejection of electrons from a metal nanotip in the half-cycle of the pulse electric field, or flipping of a single magnetic vortex lying in the center of a permalloy disk. These nonlinear phenomena are intrinsically sensitive to the carrier-envelope phase of the pulse, or the phase difference between the peak of the rapidly oscillating electric field and the slowly varying intensity distribution of the pulse. Currently there is no way to easily manipulate the locked phase of a THz pulse generated using femtosecond lasers and nonlinear optics. In this project, we will develop a simple and easily implemented method for changing the carrier envelope phase of a THz pulse.

The student will be engaged in numerical modelling and experimental testing and verification of a new method for shifting the carrier envelope phase of a THz pulse via reflection from a distributed conductive media. They will perform both transfer matrix calculations (1D) and finite difference time domain calculations to define the geometry and material parameters required for the appropriate phase shift. Testing will be performed in the Cooke lab using several homebuilt time-domain THz spectrometers. If successful, the student will have the opportunity to participate in an experiment at the Advanced Laser Light Source whereby the polarity of a magnetic vortex is flipped with a phase shifted THz pulse and time-resolved using short x-ray pulse. The work will also serve as an experimental test of a theoretical optics paper published recently, and is therefore a publishable result with the student as a first author.

For more information contact: David Cooke (cooke at physics dot mcgill dot ca).

Posted on 2018/02/08

DNA-DNA and protein-DNA interactions are crucial to cellular processes, with errors in these reactions sometimes leading to genetic diseases such as cancer. Modern confinement microscopy techniques allow for multiple, independent interactions to be visualized at once, allowing for measurements of both the expected behaviour, as well as deviations from the norm. These techniques are currently limited by fluorescent labeling techniques that alter the biophysical behaviour of the DNA molecules themselves.

For this project, the student will work on optimizing a novel fluorescent labeling technique generated in the Leslie Lab, and apply two-colour confinement microscopy to perform Förster Resonance Energy Transfer (FRET) on plasmid DNA molecules labeled with two fluorophores. These fluorophores will be placed around a known DNA unwinding site, predicted using a statistical mechanical model. These fluorophores are close enough to each other that when the site is unwound, this site will produce a FRET signal; conversely, no FRET signal willl be obtained when the site is in its native wound form as they will be too far apart. Using this novel technique, it will be possible to tease out important structural mechanics and dynamics unmeasurable with conventional microscopy techniques.

The student will receive hands-on training in confinement microscopy as well as sample design and preparation, and work closely with a graduate student on this project. Weekly meetings with the supervisor and collaborators, and daily interactions with members of the research group, will support and guide the project. Anticipated outcomes of the summer research project include presentations at local conferences and workshops, providing the student with key training in writing and oral communication.

For more information contact: Sabrina Leslie (sleslie at physics dot mcgill dot ca).

Posted on 2018/02/12

Particle physics aims to understand matter, space and time, and to unify all observables under a single theory of particles and their interactions. Known matter is made out 2 quarks (e.g. pions or kaons) or 3 quarks (e.g. protons). But states with higher numbers are not forbidden by the Standard Model of particle physics. Do they exist? Data taken by the ATLAS experiment at the LHC or the research centre CERN might reveal such states. The proposed project would call for the observation of kaons and see if two such kaons might come from a possible tetraquark state.

The project would call for familiarization with the standard analysis packages, development of tools for event selection and detailed estimations of the backgrounds. Part of the work will be based on previous expertise in the research group. Knowledge of C++ and basic understanding of particle physics concepts would be assets. Close and daily supervision would be organised.

For more information contact: François Corriveau (corriveau at physics dot mcgill dot ca).

Posted on 2018/02/13

Rapid growth of supermassive black holes (SMBHs) occurs when gas and dust flow to the innermost regions of a galaxy, spiraling into a hot, bright accretion disk, and falling across the event horizon (hence disappearing from view). Inflowing gas is also responsible for star formation in the galactic bulge. The bulge and the central black hole may even be connected via physical process that are not well understood, a connection across nine orders of magnitude! One candidate is feedback, wherein jets and winds from the accretion disk regulate both the growth of the central black hole (at small scales) and star formation (at much larger ones). During growth cycles, accreting SMBH are highly variable, since the accretion disk, jets, and winds are all dynamic structures. This summer project involves study of accretion onto our closest supermassive black hole, Sgr A*, and other active galactic nuclei (AGN).

The student will develop Python and other specialize coding skills as they analyze Chandra X-ray Observatory and other multiwavelength data. They will learn model fitting and error analysis, and develop both written and oral presentation skills.

Weekly meetings with the supervisor and daily interactions with other members of Professor Haggard's astronomy group will keep the research on track. A written report will be submitted at the end of the summer.

For more information contact: Daryl Haggard (haggardd at physics dot mcgill dot ca).

Posted on 2018/02/14

The next generation of cosmic microwave background (CMB) experiments will cast new light on the origin and fate of the universe. A new generation of CMB telescopes are being developed and require new technology. Because the detectors used to measure the CMB have very low (atto-watt) noise levels, highly sensitive circuitry is required to read them out. These circuits are held at cryogenic temperatures in order to take advantage of their extremely low impedance of superconductor elements. Current readout systems employ SQUIDs (Superconducting QUantum Interference Devices) to amplify detector signals, but these devices require frequent tuning and can have a highly non-linear response. It is of interest to investigate amplification through alternate means.

The student will participate in the testing and characterization of one such alternate system. This will involve preparation and operation of the system in its cryogenic environment, performing signal noise analysis, and the design and implementation of new or replacement features, should the need arise.

The student will be involved the the simulation and optimization of the amplifier circuit, prototyping, and testing in the cryogenic environment. This includes (1) performance evaluation, testing and quality control of the production electronics, (2) software algorithm development and coding, (3) experiment simulations, and (4) analysis of experimental data.

The student will work closely with graduate students and engineers in the group and meet with Prof. Dobbs roughly twice per week.

For more information contact: Matt Dobbs (matt dot dobbs at mcgill dot ca).

Posted on 2018/02/15

Many models beyond the Standard Model of particle physics predict the existence of cosmic strings, which are topological defects formed in a phase transition in the early universe. They are described by the dimensionless number G_μ, where G is Newton's gravitational constant and μ is the string tension. Current limits on cosmic strings provide the constraint G_μ < 1.5 × 10^-7, which rules out certain Grand Unified particle physics models with very high scale symmetry breaking. Since they are lines of trapped energy density, cosmic strings can curve space-time and have important effects in cosmology.

When cosmic strings move through plasma in the early universe, matter accretes in their wake which leaves localized regions of planar overdensity. Since these regions of overdensity remain in gas clouds after the cosmic strings have decayed, then in principle, they can be detected in 21cm redshift surveys. Ridgelet statistics, in particular, can be used to filter Gaussian noise in astrophysical data while leaving planar signals intact. Therefore, your task will be to write an algorithm that utilizes ridgelet statistics in order to detect planar signals left by cosmic string wakes in 21cm surveys.

In order to fulfill this task, you will learn the basics of cosmology, topological defects formation, and wavelet statistics by reviewing papers on these topics. Then, you will study the signature of cosmic string wakes in cosmological N-body simulations created by graduate students in our research group. Since the project involves a lot of programming, knowledge of Python, Matlab or any other programming language is a very valuable asset, but not required. Any result you will obtain from the simulations will set the groundwork for cosmic string wake detection in astrophysical data.

Weekly meetings will be held in order to keep track of your progress. In addition, the other graduate students working on the project will be there to help you when you need it.

For more information contact: Robert Brandenberger (rhb at physics dot mcgill dot ca).

Posted on 2018/02/20

The discovery of GW170817, the first neutron star collision detected via both gravitational waves (GW) and electromagnetic (EM) radiation, has ushered in a new era of multimessanger astrophysics. The Haggard group at McGill successfully led observations of GW170817 with the Chandra X-ray Observatory and joined the massive observational effort to characterize this revolutionary astrophysical source. The LIGO-Virgo detectors have also enabled the first unambiguous detections of binary black hole mergers, while detection of the first neutron star-black hole merger is still on the horizon. Localization of upcoming GW targets will continue to be a crucial step in connecting these GW events to astrophysics, by associating the GW source with an EM emitter and a galaxy/stellar population. This summer project aims to build on our success by further studying GW170817 and/or designing new sensitive, high-resolution EM follow-up programs for localization and characterization of new GW discoveries.

The student will develop Python and other specialize coding skills as they analyze Chandra X-ray Observatory and other multiwavelength data. They will learn model fitting and error analysis, and develop both written and oral presentation skills.

Weekly meetings with the supervisor and daily interactions with other members of Professor Haggard's astronomy group will keep the research on track. A written report will be submitted at the end of the summer.

For more information contact: Daryl Haggard (haggardd at physics dot mcgill dot ca).

Posted on 2018/02/20

Collective decision of immune cells encode immunogenic information in a complex way. Various cytokines have been observed to display different scaling properties: for instance IL-2 concentrations scale with the number of antigen presented, but not with the number of cells presented, which is counterintuitive and suggests a non trivial collective computation. The goal of the project is to model such collective decision. The student will learn and use the evolutionary algorithms developed in the group to evolve networks performing proper such scaling of response. He/she will have daily meetings with the supervisor, as well as regular interactions with all members of the group.

For more information contact: Paul François (paulf at physics dot mcgill dot ca).

Posted on 2018/02/22

Fluctuations that look self-similar at different length scales appear in many systems, be they thermal fluctuations at phase transitions near critical points or quantum fluctuations in particle physics. An important challenge in all cases is to theoretically predict the critical exponents, which control the spectrum of fluctuations. Important progress can be made by exploiting that scale invariance often implies conformal symmetry. This has recently led to a new numerical method, the conformal bootstrap, which allows to solve interesting critical points, including one at the endpoint of the liquid-gas phase transition in water. The goal of this project will be to implement analytic formulas which approach this numerical solution.

The student's task will be to develop Mathematica code to efficiently evaluate and simplify group-theoretic integrals which appear in analytic formulas. They will learn skills for symbolic programming and numerical analysis, and develop both written and oral presentation skills.

In addition to weekly meeting with the supervisor, the student will benefit from daily interactions with other members of Professor Caron-Huot's high-energy physics group. A written report will be submitted at the end of the summer.

For more information contact: Simon Caron-Huot (schuot at physics dot mcgill dot ca).

Posted on 2018/02/22

An emerging branch of nanotechnology is motivated by the application of nanoparticles in the nutraceutical and cosmetic industries. This research project will use single-particle confinement microscopy to investigate the biophysical properties, stoichiometry and kinetics of nanoparticle assemblies and their interactions. This technique entraps particles in reaction volumes as small as femto-liters and allows prolonged monitoring of reaction trajectories. It also enables direct visualization of interactions between chemical species and nanoparticles, while introducing reagents in real time and monitoring the responses.

For this project, the student will develop analysis approaches to quantify probe-nanoparticle interactions (e.g. binding/unbinding kinetics, encapsulation dynamics and adsorption kinetics). The student will receive training in quantitative image analysis (Matlab) as well as hands-on training in confinement microscopy and will work closely with a research fellow and graduate student. Weekly meetings with the supervisor and collaborators, and daily interactions with members of the research group, will support and guide the project. Anticipated outcomes of the summer research project include presentations at local conferences and workshops, providing the student with key training in written and oral communication.

For more information contact: Sabrina Leslie (sleslie at physics dot mcgill dot ca).

Posted on 2018/02/22

In a typical high-energy collision at particle colliders, a host of elementary particles are produced which were not initially present. The probability to produce a given set is equal to the square of a quantum-mechanical "scattering amplitude". A diagrammatic recipe due to Feynman allows to calculate these amplitudes for any process in the Standard Model. Surprisingly, the results often admit concise analytic formulas that are much simpler than the recipe. The goal of this project will be to implement a recent method, which exploits symmetries and general principles, to obtain analytic formulas for amplitudes involving heavy particles.

The student's task will be to develop code implementing new formulas, and compare numerically with the output of public computer packages. They will learn skills for symbolic programming (Mathematica), and develop both written and oral presentation skills.

In addition to weekly meeting with the supervisor, the student will benefit from daily interactions with other members of Professor Caron-Huot's high-energy physics group. A written report will be submitted at the end of the summer.

For more information contact: Simon Caron-Huot (schuot at physics dot mcgill dot ca).

Posted on 2018/02/23