Gravity Group Lunch Seminar
May 5, 2017
Benjamin A. Mazin, UCSB
Microwave Kinetic Inductance Detectors for High Contrast Imaging
Microwave Kinetic Inductance Detectors, or MKIDs, are superconducting detector arrays that can measure the energy and arrival time of individual optical through near-IR photons without read noise or dark current. I will report on the promising commissioning and first science results of the first two MKID Integral Field Spectrographs (IFSs) for high contrast imaging, the DARKNESS/SDC instrument at Palomar and the MEC/SCExAO instrument on Subaru. Future upgrades to integrate the MKID IFS as a focal plane wavefront sensor to implement active speckle nulling will be discussed, as well as the potential for these instruments on ELTs. I will also touch on the potential of these detectors in a wide range of other astronomical applications.
April 28, 2017
Chiara Mingarelli, Max Planck
Insights into Supermassive Black Hole Mergers, Stalling and Demographics with Pulsar Timing Arrays
Galaxy mergers are a standard aspect of galaxy formation and evolution, and likely all large galaxies contain central supermassive black holes (SMBH). Here I discuss a new bottom-up approach to identifying continuous nanohertz gravitational wave (GW) host galaxies by using massive elliptical galaxies in the 2 Micron All Sky Survey, assessing the likelihood of detecting one of these sources with Pulsar Timing Arrays (PTAs), their contribution to the GW background and its anisotropy, and report on the characteristics of the most detected SMBH binaries and host galaxies. We find that out to 225 Mpc there are on average 91 sources emitting GWs in the PTA band and 7 stalled binaries. The chance of detecting these GW sources with current PTA data is <1%, however in the next 10 years PTAs probe a region of the parameter space rich in sources, making a 3-sigma (or better) detection likely, depending on the source position of the sky and the ability to subtract the GW background.
April 21, 2017
Cristobal Sifon, Princeton University
Weak Lensing masses of galaxies in galaxy clusters, from LRGs to UDGs
We present a direct measurement of the masses of subhalos hosting galaxies in massive, low-redshift galaxy clusters using weak gravitational lensing. We constrain the average subhalo mass as a function of stellar mass to probe the total-to-stellar mass relation of satellite galaxies and discuss our results in the context of the analogous total-to-stellar mass relation for central galaxies, and numerical predictions for the total-to-stellar mass relation of subhalos. We separately constrain the total masses as a function of cluster-centric distance to assess any level of mass segregation and tidal stripping within clusters. Similar to the total-to-stellar mass relation, we put our results in context with the aid of semi-analytical predictions for the resulting mass segregation in numerical simulations. Finally, we present weak lensing constraints on the average mass of subhalos hosting UDGs in massive clusters, and discuss the implications of our results and possible ways forward.
April 12, 2017
Speaker 1: Kimmy Wu, UC Berkeley
CMB Polarization B-mode Delensing with SPTpol and Herschel
Inflation generically predicts a background of primordial gravitational waves, which generate a primordial B-mode component in the polarization of the cosmic microwave background (CMB). The measurement of such B-mode signature will lend significant support for inflation and will be important for development of quantum gravity theories. Observed B modes in addition contains a lensing component from gravitational lensing of primordial E modes. This component obscures the measurement of the primordial B modes and if the primordial B-modes are sufficiently small, it will need to be cleaned in a process called "delensing." Delensing has been studied theoretically and with simulations but has not been demonstrated with data until now. I will present delensing of a measurement of the CMB B-mode power spectrum from SPTpol using data from Herschel as a tracer of the lensing potential. The measured B-mode power is reduced by 28 percent, in agreement with predictions from simulations, and the null hypothesis of no-delensing is ruled out at 6.9 sigma. This work represents a crucial step on the road to detecting primordial gravitational waves.
Speaker 2: Adam Anderson, Fermilab and University of Chicago
SPT3G: Development and Deployment of a New Camera for the South Pole Telescope
The third-generation camera for the South Pole Telescope, SPT3G, was deployed in early 2017 to map the cosmic microwave background at 90, 150, and 220 GHz with 16,000 detectors. This represents a factor of 10 increase in detector count compared with the previous generation receiver on the SPT, made possible by a new multichroic pixel architecture, developments in frequency-domain multiplexing readout electronics, and an upgraded optical design. The increased sensitivity of SPT3G will enable a diverse set of measurements on primordial B-mode polarization, gravitational lensing of the CMB, and the E-mode damping tail. The new camera is currently taking engineering data to characterize and optimize its performance. I will discuss the science motivation, instrument development, and current status of this new camera.
April 7, 2017
Simon Foreman, CITA
Cosmic shear a a probe of galaxy formation physics
The precision of current and future cosmological observations at Megaparsec scales demands a detailed understanding of the effects of baryonic processes on the clustering of matter at these scales. In this talk, I will explore how to use measurements of cosmic shear to constrain the impact of these processes on the total matter power spectrum. I will present forecasts demonstrating that shear measurements from Stage III surveys (such as DES and HSC) and beyond will be able to strongly constrain (or even rule out) current simulation-based implementations of baryonic physics (such as AGN feedback). These forecasts make use of a model-independent parametrization of the impact of baryons on the matter power spectrum, and marginalize over several key observational and theoretical systematics. The results indicate that cosmic shear can likely be used as a robust probe of the physics of galaxy formation, and provide an important observational input for future simulations or modeling efforts.
March 31, 2017
Will Coulton, Princeton University
Cosmology and astrophysics from the bispectrum
The three point function of the cosmic microwave background (CMB) is an ideal place to study CMB secondary sources as there is no noise bias and CMB secondaries are the dominant contribution. In this talk I will discuss my work measuring the bispectrum from radio galaxies, dusty star forming galaxies and thermal Sunyaev Zel'dovich sources in ACT and Planck maps. I will then discuss what we hope to learn from the bispectrum with ongoing surveys.
February 17, 2017
Jon Gudmundsson, NORDITA and Stockholm University, Sweden
Probing the calibration of the Planck satellite using Mars and the four outer planets
The planets in our solar system provide a valuable calibration source for experiments designed to probe the cosmic microwave background (CMB).
In this talk, I will describe how the Planck satellite used Mars, Jupiter, Saturn, Uranus, and Neptune to characterize its spatial (beam) and spectral response functions. I will also discuss how the observations of those planets helped provide an independent handle on the cross-calibration of Planck and WMAP, suggesting that the two satellite experiments are consistent in their absolute calibration at the percent-level. During the talk, I will try to emphasize some of the subtleties that we encountered during this work and discuss how it might relate to calibration work for future CMB experiments which, if they are to reach their science goals, are facing stringent instrument characterization requirements.
(This work is described in https://arxiv.org/abs/1612.07151 )
February 10, 2017
Ed Young, Princeton University
Deprojection: Application to the SPIDER data
In this talk, I'll introduce the basics of deprojection, then discuss its implementation in the SPIDER analysis pipeline.
Justin Ripley, Princeton University
Black hole horizons and hydrodynamics
The advent of gravitational wave astronomy allows for gravity to be tested in the extreme gravity regime, where the deviations from Newtonian gravity are large and the characteristic velocities of the problem are changing at speeds comparable to the speed of light.Exploring the extreme gravity regime will allow for strong constraints to be placed on the physics of black hole horizons. We will outline an intriguing observation, first made by Damour in the 70's, that the dynamics of black hole horizons obey a Navier-Stokes like equation. We will comment on the possibility of modeling alternatives to black holes using a hydrodynamic model of the horizon.
March 3, 2017
Herman Verlinde, Princeton University
Discussion of emergent gravity and the dark universe
February 24, 2017
Cyrille Doux, APC, France
Cosmic microwave background lensing and Lyman-α forest bispectrum
Cosmic microwave background (CMB) gravitational lensing probes the matter density field integrated along the line of sight and traces large-scale fluctuations, while the Lyman-α forest in the spectra of quasars traces small-scale fluctuations in the neutral hydrogen density field. For each Lyman-α forest in SDSS-III/BOSS DR12, we correlate the one-dimensional power spectrum with the cosmic microwave background lensing convergence on the same line of sight from Planck. This measurement constitutes a position-dependent power spectrum, or a squeezed bispectrum, and quantifies the nonlinear response of the Lyman-α forest power spectrum to a large-scale overdensity. In this talk, I will present this theoretical approach, the measurement, and the possible use of this new observable in the future as an independent test of our understanding of the relation between intergalactic gas and dark matter.
February 17, 2017
Lasha Berezhiani, Princeton University
Cosmic Acceleration without Dark Energy
Cosmic acceleration is widely believed to require either a source of negative pressure (i.e., dark energy), or a modification of gravity, which necessarily implies new degrees of freedom beyond those of Einstein gravity. In this talk I will present a third possibility, using only dark matter and ordinary matter. The mechanism relies on the coupling between dark matter and ordinary matter through an effective metric. Dark matter couples to an Einstein-frame metric, and experiences a matter-dominated, decelerating cosmology up to the present time.
Ordinary matter couples to an effective metric that depends also on the DM density, in such a way that it experiences late-time acceleration.
Assuming a simple parametrization of the effective metric, we show that our model can successfully match a set of basic cosmological observables. To get a growth history similar to the ΛCDM prediction, our model predicts a higher H0, closer to the value preferred by direct estimates. On the flip side, we tend to overpredict the growth of structure whenever H0 is comparable to the Planck preferred value. The model also tends to predict larger redshift-space distortions at low redshift than ΛCDM.
February 10, 2017
Marc Casals, CBPF (Brazil)
Classical Instability, Tails and Self-force on a Rotating Black Hole Space-time
In this talk I will present recent results on linear field perturbations of a rotating (Kerr) black hole on two different settings. On the first setting, I will present results on the propagation of fields around a Kerr black hole and, particularly, its behaviour at late times. For a non-extremal black hole, we find a logarithmic decay that appears before a well-known power-law tail decay. For an extremal black hole, on the other hand, Aretakis found a horizon instability in the case of axisymmetric modes. We obtain the precise growth-rate for these modes and find an enhanced growth-rate in the case of non-axisymmetric modes.
On the second setting, I will present results on the calculation of gauge-invariant quantities in Kerr within the framework of the gravitational self-force program for modelling black hole inspirals in the extreme mass-ratio.
February 3, 2017
Roberto Puddu, PUC de Chile
QUBIC and the bolometric interferometry concept
Nowadays most effort in cosmology is devoted to the detection of B-mode polarization pattern of the CMB, the smoking gun to prove the inflationary scenario. Since the amplitude of this signal is expected to be of the order of fractions of uK, sensitive instruments with an exquisite control of systematics and kilopixel arrays of low noise detectors are required. In this context QUBIC, a ground-based experiment exploiting the technique of bolometric interferometry, is being developed. The first module will be installed in Argentina and it will observe the sky in two frequency bands centered at 150 and 220 GHz. A second module will be deployed in Antarctica with two further frequency bands centered at 90 and 300 GHz. The absence of warm optics will minimize cross polarization, while a cold half wave plate will allow optimal modulation of the sky signal. Thanks to the bolometric interferometry, QUBIC will combine the exquisite control of systematics provided by interferometry with the extremely low noise of bolometric detectors. Moreover, self calibration will take advantage of baselines redundancy to control systematics. I will present the main aspects of QUBIC, focusing on the challenging coupling of interferometry with broadband detectors such as bolometers, and providing an update of its current state-of-art.
January 27, 2017
Corwin Shiu, Princeton University
Design and performance of planar-wideband slotted bow-tie antennas for CMB detection
Current antenna-coupled TES bolometers can achieve 30% bandwidth, which cover the spectral window for CMB observation. However, to fully characterize galactic synchrotron emissions (20-60GHz) and galactic dust (180-310GHz) we need additional bandwidth. In this talk, I will report on ongoing work to develop wideband phased-antenna arrays that would be suitable for a BICEP/KECK/SPIDER focal plane. We will discuss design choices and challenges of this detector geometry, and show measured antenna performance.
Vy Luu, Princeton University
SuperBIT's three-mirror anastigmat optics upgrade
SuperBIT is a sub-arcsecond imaging telescope designed to achieve high stability (0.02 arcsec) over a wide field-of-view (0.5 deg) for deep single exposures of up to 5 minutes at visible and near UV/IR wavelengths. It aims to obtain astronomical images with highly angularly resolved background galaxies and stable PSFs, which are well-suited for shape measurements in gravitational lensing. In this talk, I am discussing the status of the current optics, motivation for upgrading and the upgraded optics design -- a three-mirror anastigmat -- for the next-generation SuperBIT.
January 20, 2017
Johan Samsing, Princeton University
Dynamical Formation of High-Eccentricity Gravitational Wave Mergers and Nuclear Transients
In this talk, I will present my recent work on few-body interactions involving white dwarfs, neutron stars, and black holes. I will especially discuss the effects of including tidal couplings and general relativistic effects in the N-body equation of motion, corrections that currently are omitted in many new state-of-the-art codes. The inclusion of such dissipative terms leads to much higher merger rates, and plays a key role in describing the rate of high-eccentricity black hole / neutron star gravitational wave (GW) mergers and white dwarf disruptions. This has several observable consequences for both LIGO and LISA. I will also show how triple black hole interactions in AGN disks might lead to double GW merger events. Many of my results in this talk will be based on a new analytical solution I recently found to the chaotic three-body problem with tides and GW emission included in the equation of motion.
January 13, 2017
Simone Aiola, Princeton University
From Time-Ordered Data to Cosmology with the Atacama Cosmology Telescope
The bolometric polarimeter at the focal plane of the Atacama Cosmology telescope (ACTPol) allows us to map the Cosmic Microwave Background (CMB) with high signal-to-noise both in temperature and polarization. These sensitive measurements require an exquisite understanding of the systematic effects that can potentially bias the reconstructed CMB maps, and thus any cosmological result inferred from those.
In this talk, I will present the map-making pipeline, especially focusing on how known systematic effects have been characterized and removed during the mapping process. I will briefly show the two-season cosmological results presented in Louis et al. (2016), and describe the current effort to finalize the analysis of all three ACTPol seasons. I will conclude with an overview of the recent
measurement of the kinematic Sunyaev-Zel’dovich effect using the pair-wise momentum estimator from De Bernardis et al. (2016).
December 16, 2016
Steven Benton, Princeton University
Report on SuperBIT's 2016 Test Flight
SuperBIT is a wide-field sub-arcsecond imaging telescope for visible and near UV/IR wavelengths. It is designed to operate in the space-like environment of the Super-Pressure Balloon platform at an altitude of 35 km. During a 100 day flight it will infer masses of hundreds of galaxy clusters via weak lensing. On June 30, 2016, SuperBIT flew a one-night test flight from Palestine, TX. In this talk I report on the integration campaign, test flight, and plans for the ultra-long duration science flight.
Shuay-Pwu (Patty) Ho, Princeton University
Developments of ground-based detectors for CMB and the performance of the 1st high density array for AdvACT
I will start with the current developments of CMB ground-based detectors. Better detector sensitivity and larger number of pixel counts, coupled with optical designs are critical for CMB detections. A summary of the bolometer sensitivities and array sizes of several ground based telescopes in recent years will be shown. Then I will focus on the first array of AdvACT, which was recently deployed and began its observations. This array features ~2000 AlMn transition edge sensor bolometers operating at 150 and 230 GHz. I will review all details of its detector optimization, the array assembly and the array characterization.
Special Seminar, Wednesday, December 14, 2016
Johanna Nagy "Probing Inflation with SPIDER, a Balloon-Borne CMB Polarimeter"
The generation of a stochastic gravitational wave background is a key prediction of cosmological theories of inflation. At large angular scales, these gravitational waves would imprint a "B-mode" polarization pattern in the Cosmic Microwave Background, providing a new window into the physics of the early universe. SPIDER is a balloon-borne telescope that has been uniquely optimized to search for the inflationary B-mode signature in the CMB. Over the course of two Antarctic flights, SPIDER will make polarization maps over 10% of the sky in three frequency bands with degree-scale angular resolution. After an overview of the instrument and science goals, preliminary results from SPIDER’s 2015 flight will be presented along with a summary of progress towards the second flight.
December 09, 2016
Mathew Madhavacheril, Princeton University
Cosmology with the Longest Lever Arm using CMB Lensing
The cosmic microwave background (CMB) provides a snapshot of the universe at a redshift of around 1100. At the same time, it acts as a backlight that is gravitationally lensed by structure that formed at low redshifts. CMB fluctuations are therefore especially sensitive to physics that becomes influential at late-times such as dark energy and neutrino mass. Recent measurements from the Planck satellite indicate a tension between the amplitude of structure measured at low redshifts and that expected from the primary CMB alone. Ongoing high-resolution CMB experiments like the Atacama Cosmology Telescope (ACT) and planned experiments including the Simons Observatory and CMB Stage IV will significantly improve the precision on cosmological parameters and clarify these tensions. I will survey the status and prospects of using CMB lensing in conjunction with low-redshift optical and spectroscopic probes to constrain the properties of neutrinos and dark energy.
December 02, 2016
Francois Boulanger, Institut d'Astrophysique Spatiale
The interstellar B-fields crossing primordial CMB B-modes
Planck, as well as balloon and ground based experiments, have measured the polarization of the sky at sub-mm and mm wavelengths with unprecedented sensitivity. The data analysis involves research in cosmology and Galactic astrophysics, which might lead to a major discovery for fundamental physics. The main goal is to characterise anisotropies in polarization of the Cosmic Microwave Background (CMB) with sufficient precision and confidence to detect the expected signature from primordial gravitational waves. At the same time, we are getting the data needed to characterise interstellar polarization and magnetic fields in the diffuse interstellar medium and molecular clouds.
The analysis of Planck data has led to a statistical modelling of dust emission as a foreground to CMB polarization, which may be used to optimize and assess component separation. I will review this work in the context of future CMB experiments.
November 18, 2016
Stephan Schlamminger, NIST
Measurements of the gravitational constant - why is a precise measurement so difficult?
In this presentation, I will summarize measurements of the Newtonian constant of gravitation, big G, that have been carried out in the last 30 years. I will describe key techniques that were used by researchers around the world to determine G. Unfortunately, the data set is inconsistent with itself under the assumption that the gravitational constant does not vary in space or time, an assumption that has been tested by other experiments. Currently, several research groups have reported measurements with relative uncertainties below 2 x 10^-5, however, the relative difference between the smallest and largest reported number exceeds 5x10^-4. It is embarrassing that after over 200 years of measuring the gravitational constant, we do not have a better understanding of the numerical value of this constant. I will discuss why it is so difficult to measure G and what can be done to get a better understanding of these experiments.
November 11, 2016
Anna Ijjas, Paul Steinhardt
Early-Universe Boot-camp Part III: The truth about bounces
This will be the third part of the early-universe boot-camp in which we will focus on cosmologies that replace a big bang with a big bounce. We will explain how, in these scenarios, the large-scale structure of the universe is determined during a contracting phase before the bounce and will describe the recent development of the first well-behaved cosmological bounce solutions.
November 09, 2016
Warm Dark Matter Cosmologies: in theory and simulations
Warm dark matter models are a viable alternative to the cold dark matter models challenged by many recent observations (e.g. dwarf galaxies, pure-disk galaxies, matter distribution in voids) and by the narrowed detection limits. I will review some theoretical assumptions made in describing the properties and behavior of different WDM candidates (in a wide mass range) and discuss the constraints from simulation results in the astrophysical contexts at both large and small scales.
The intrinsic properties of WDM particles, strongly dependent on the assumed particle model and production mechanism, imprint a distinct signature on the structure formation and evolution. Using N-body cosmological simulations I will show that the structure formation mechanism in WDM is qualitatively different than in the CDM scenario and more complex than originally assumed - a 'hybrid' between 'top-down' and 'bottom-up' clustering on multiple scales - depending locally on the morphology of the analyzed region and globally on the free streaming length of the simulated particle. On smaller scales, the properties of WDM particles influence the shape and outlook of halos - caustics and shells and their internal structure - density and phase space density profiles.
I will also comment on the technical aspects in simulating WDM and describe possible observational tests for distinguishing between dark matter models.
Location: 303 Jadwin Hall
Time: 3:00 PM
October 28, 2016
Jonathan Blackman, CIT
Surrogate models of gravitational waveforms from numerical relativity simulations of black hole mergers
GW150914 was the first detection of gravitational waves from a binary black hole merger, bringing us into the era of gravitational wave astronomy. From such gravitational wave detections, we can put constraints on deviations from general relativity (GR), as well as measure the masses and spins of the black holes involved in the merger.
Such measurements require knowledge of the gravitational waveforms predicted by GR for all relevant masses and spins. Numerical relativity (NR) simulations are now sufficiently robust that we can accurately simulate binary black hole mergers and obtain the waveform for all but the most extreme parameters, but they are too computationally expensive for a dense coverage of the parameter space. The effective-one-body model and phenomenological waveform models agree well with NR for the parameters of GW150914, but could be insufficiently accurate for estimating the parameters of a loud gravitational wave detection in other regions of the parameter space. NR surrogate models attempt to rapidly and accurately interpolate the waveforms from a set of NR simulations over a subset of parameter space. Using the Spectral Einstein Code (SpEC), we have built NR surrogate models for non-spinning binaries with mass ratios up to 10, and for spinning precessing binaries with a restricted spin direction on the smaller black hole. They typically perform an order of magnitude better than other waveform models when compared to NR waveforms which were not included in the surrogate training set, and can be used in gravitational wave parameter estimation.
Stevie Bergman (short talk) Magnetic Shielding of the Spider Receivers
October 21, 2016
Adam Burrows, Astrophysics
A brief update from the mid-decadal report
Ben Racine, University of Oslo
B modes and component separation: the Gibbs sampling solution
Detecting B-modes due to inflationary gravitational waves in the polarization of the Cosmic Microwave Background is one of the greatest goals of modern observational cosmology. Many experiments have been designed to detect this weak signal, and upper limits are improving year by year. In fact, while B-modes have now been clearly observed, these are not of inflationary origin, but rather induced by late time effects.
At large scales, the signal is most probably dominated by the galactic dust, whereas at small scale, it is due to gravitational lensing. In this talk I will show some recent observational highlights, review the problem of component separation, and present a recently developed method for joint estimation of cosmological parameters and astrophysical foregrounds. Finally, I will discuss how this may be applied to observations from the SPIDER experiment.
October 14, 2016
Paul Steinhardt & Anna Ijjas
Early Universe Bootcamp, Part 2
These two meetings will be a frank examination of current theories of the origin and evolution of the large-scale structure of the universe, especially aimed at experimentalists and observers, with ample time for questions and discussion.
October 7, 2016
Paul Steinhardt, Anna Ijjas et al.
Early Universe Bootcamp, Part 1
These two meetings will be a frank examination of current theories of the origin and evolution of the large-scale structure of the universe, especially aimed at experimentalists and observers, with ample time for questions and discussion.
The first meeting will focus primarily on big bang inflationary cosmology; the second will continue the discussion and introduce bouncing cosmology, including some recent advances.
September 30, 2016
Marc Kamionkowski, Johns Hopkins University
Dust polarization and interstellar turbulence
Perhaps the most surprising result from the Planck satellite is the observation that the E-mode power in the dust polarization is twice that in the B mode, in stark contrast to pre-Planck expectations of roughly equal dust powers in E and B modes.
I will show how the E- and B-mode powers are determined by fluctuations in the magnetized interstellar medium, the slow, fast, and Alfv\'en magnetohydrodynamic (MHD) waves. I will argue that the observed E/B ratio, as well as the TE (temperature-polarization) cross-correlation (which is observed to be positive) are not easily reconciled with expectations for the spectrum of fluctuations expected in the models of MHD turbulence usually invoked to account for the fluctuations. I will then discuss some alternative explanations (including the possibility that the scales probed by Planck overlap the outer scale for interstellar turbulence) for the dust-emission patterns seen in the Planck temperature-polarization maps.
I will then outline some interesting directions for future related research.
Sep 23, 2016
Ira Thorpe, Goddard Space Flight Center
The success of LISA Pathfinder and the prospects for a space-based gravitational wave observatory.
A space-based gravitational wave observatory targeting the milliHertz frequency band has the potential to inform many areas of physics and astrophysics including the nature of gravity in the strong-field limit, the formation and growth of massive black holes and their host galaxies, and the demographics of stellar compact objects. This strong science case has led to the Laser Interferometer Space Antenna (LISA) mission concept consistently receiving high rankings in major reviews in both the US and Europe. In 2016, the ESA-led LISA Pathfinder mission validated several key technologies for LISA and further strengthened the case for a timely implementation of LISA. In this talk, I will discuss the preliminary results from LISA Pathfinder and the outlook for a LISA-like mission in light of the successes of Pathfinder and LIGO.
Huan Yang (short talk)
Global Crustal Dynamics of Magnetars in Relation to Their Transient X-ray Outbursts", based on arXiv:1608.02633
In this talk, I will briefly discuss the yielding response of a neutron star crust to smooth, unbalanced Maxwell stresses imposed at the core-crust boundary, and the coupling of the dynamic crust to the external magnetic field. We have developed a global and time-dependent model of elastic, plastic, magnetic, and thermal evolution. Such model provides an unified framework to understand various Magnetar bursts: the (~0.1s) short bursts, and giant flares and quasi-periodic oscillations (QPOs).