CMB-S4 Collaboration Meeting Fireslides

Wednesday August 2, 2023

Fireslide instructions

• Add your fireslide to this deck and be sure that your name is prominently displayed at the top.
• All fireslides MUST be added to this deck prior to the end of the day on Tuesday, August 1.
• If you are presenting remotely, please indicate that at the top of your slide.
• You will have up to one minute to present your fireslide.

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Zhumabek, Denissenya, Linder 2306.03154

Connecting Primordial Gravitational Waves and Dark Energy

grad Y3

postdoc

N=50-60

Quintessential inflation to unify early and late time acceleration.

Protect with symmetries and pole structure – 𝛂-attractors!

Universality: n_s = 1-2/N, r = 12𝛂/N²

Dark energy attractor: w_∞ = -1+2/(9𝛂)

Note r ~ 1/(1+ w_∞). Thawing dynamics relates w_∞ to w₀, w_a.

Kallosh & Linde 1306.5220

If don’t see GW, will see DE dynamics; if don’t see DE dynamics, will see GW!

Starobinsky inflation

Eric Linder (online)

Improving Constraints on Models Addressing the Hubble Tension with CMB Delensing

Joshua Ange (2nd Year Undergrad at SMU), Joel Meyers (Online); Based on arXiv:2307.01662

CMB lensing smooths peaks; delensing sharpens peaks

H₀ and related parameters affect peak locations

• Sharper peaks can be better localized, leading to tighter constraints on parameters affecting peak positions

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• Delensing provides ~20% tighter constraints on models addressing Hubble tension:
• Varying Fundamental Constants
• Early Dark Energy
• Interacting Dark Radiation

See also: arXiv:1609.08143, arXiv:2111.15036, https://github.com/ctrendafilova/FisherLens, https://github.com/selimhotinli/class_delens

Multi-wavelength AGN Variability

Plots from: https://arxiv.org/abs/2302.14749

• Postdoc at University of Chicago (Online)
• Working with ACT and SPT to monitor AGN
• Correlated variabilities
• Other interesting observational properties
• Building relationships with other collaborations

John C. Hood II

New Frontiers and Challenges with Future CMB Experiments

Beyond Fisher Forecasting for Cosmology

arXiv:2211.06534 - Joseph Ryan, Brandon Stevenson, CT, Joel Meyers

Cynthia Trendafilova (they/them, she/her)

• Lensing reconstruction
• Iterative delensing
• Non-Gaussian covariance
• DALI corrections

Maps to Power Spectra

• DRAFT forecasting tool
• N_eff forecasts�[paper in prep!]
• BSM extensions

CLASS_delens�https://github.com/selimhotinli/class_delens/

FisherLens�https://github.com/ctrendafilova/FisherLens

• Likelihoods & parameter estimation

Ola Kusiak (remote)

Columbia Y4 PhD

Measuring SZ x galaxy with ACT DR6

Projected-fields kSZ2 x unWISE

tSZ x unWISE

CIB contamination → “deCIBing” (2303.08121) with Kristen Surrao and Colin Hill

Idea: Use the external LSS data that is correlated with both CIB and tSZ to remove those contaminants to enhance CMB+kSZ measurements using ILC methods

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Goal: Constrain pressure (tSZ) and density (kSZ) to infer thermodynamic profile of unWISE

The 3 new methods vary in terms of noise penalty and how well they clean out the CIB

akk2175@columbia.edu

Capse.jl: efficient and auto-diff CMB Cℓ emulation

New Julia-based CMB spectra emulator (w/ python wrapper!)

🔋Cheap to train (~1 hr on a laptop with an 8-core CPU)

⚡Blazingly fast (40 µs, about 100-1000x speed up wrt state of the art)

🎯Accurate (res err < 0.08𝛔 at all S4-relevant scales)

📈Auto-differentiable → efficient gradient-based samplers/minimizers!

Check out CosmoPower (Spurio-Mancini+22,Bolliet+23) and ClassNet (Günther+22) too!

Planck analysis

2307.14339 https://github.com/marcobonici/capse_paper

Jaime �Ruiz-Zapatero

(Oxford)

Marco

Bonici

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INAF �Milan

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Federico

Bianchini

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Stanford�SLAC

Jessica Avva Zebrowski

University of Chicago

j.z@uchicago.edu

Optimization techniques for Low-ℓ noise performance

Two main mitigation strategies:

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Subtraction of Polarized Atmosphere: A scaled version of each observation’s coadd-removed 220 GHz map is low-pass filtered, then subtracted from each observation’s 150 GHz map. This subtracts off each day’s atmosphere, observation by observation.

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Re-weighting based on PSD of Maps: The mean of the weight map of each observation (2 hours of data) is scaled by that map’s PSD between ℓ = 50-250. This takes into account correlated noise between detectors.

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2.3 x reduction in noise at ℓ = 70 since initial CMB-S4 LAT + SAT r forecasts!

=

• ​

Scaling coefficient

x

U

Q

220 GHz 2-hour map - Q

150 GHz 2-hour map - Q

Cleaned 150 GHz 2-hour map - Q

150 GHz 2-hour map - U

Matthew Young

Fermilab Postdoc

myoung@fnal.gov

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• Constraining cluster pressure profiles using SZ datasets

• CMB-S4 test cryostat window prototyping

• Instrumentation for the next generation of CMB experiments (SPT-SLIM, SPT-3G+)

What is RadioForegroundsPlus? The project has been approved as part of the Space Program within Horizon 2020 in the EU (HORIZON-CL4-2023-SPACE-01) and it is a continuation of the radioforegrounds.eu program (G.A. 687312) which has been operating between 2016 and 2018.

What are the Main Goals? Exploiting the Data from Radio and Microwave Surveys, C-BASS, QUIJOTE, S-PASS for improving our knowledge of Low Frequency Foregrounds for CMB B-Modes

For How Long will it be Operating? The approval was communicated on July 24th, the program becomes operational on January 1^st, 2024, for 3 Years.

Which Opportunities? About 1.5 Millions to Support Analysis and 2 and 3 years Post-Doc Positions in the participating institutions.

CMB-Stage IV Collaboration Meeting, Stanford, August 2nd, 2023, Thank You CMB-S4 for the Support!

Nodes: IFCA (Barreiro, Lead), IAC (Rubino-Martin), CNRS (Banday), Manchester (Chluba), Oxford (Taylor), SISSA (Baccigalupi)

Work Packages: 1-Project coordination, management and dissemination, 2 - Low-frequency data (QUIJOTE, C-BASS, S-PASS) and Planck maps, 3 - Advanced tools for component separation and foregrounds maps production 4 - Modelling the diffuse Galactic emission, 5 - Forecasted impact of radio foregrounds in future CMB experiments and preparation of products

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Carlo Baccigalupi, SISSA, On Behalf of the RF+ Consortium

Shamik Ghosh, M. Alvarez, J. Delabrouille, M. Remazeilles, E. Russier, J. Borrill, Z. Lukić

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• CMB, LSS, Galactic and extragalactic foregrounds.
• GPU acceleration using JAX. Speed up 8x.
• Plan: Forward modelling based on JAX autograd.
• Single framework for sky simulations.
• Modularity for community-contributed plug-ins.
• Production of templates for PySM and PSM.

Work funded by the LBNL LDRD program.

Results using from 7.7 Gpc box at 6144³ resolution using LPT calculated on the lightcone. Halo component now in development.

Avg. N_l 50 < l < 100:

WMAP K: 4.01x10^-3

LFI 30GHz: 3.92x10^-3

Combined: 1.79x10^-3

Improved input maps for making templates of galactic emission.

Lensing potential power validation

𝛋

𝛟

Sky simulations for Stage-4/5 experiments

An update on ongoing developments

Synchrotron Polarized Intensity

CO10

CO10 maps at (150, -45)

Type 1

Type 2

GNILC

Noise level

Exploring Reionization Astrophysics Using kSZ Beyond ℓ = 3000

Divesh Jain (remote)

NCRA-TIFR

1. Self-consistent framework to evaluate shape and amplitude of kSZ (Jain et al. 2023)

Collaboration : Tirthankar Roy Choudhury (NCRA-TIFR Pune), Suvodip Mukherjee (TIFR Mumbai)​, Srinivasan Raghunathan (University of Illinois)​

2. kSZ power variation with reionization models allowed by R21 measurement. Also shown are Cross-ILC error bars (Raghunathan & Omori 2023)

3. Model forecasts tight error bars on both homogeneous and patchy properties.

Conclusion:

Highlights the need to capture kSZ power on a broad range of multipoles to gain insights into the inhomogeneous reionization era.

Forecasts: Error bars on 𝑧₅₀ is ~ 0.50 and Patchy B-mode at ℓ=200 is at ~1.3 nK²

Has important implications for detecting patchy reionization signal.

Jain et. al. in prep

R21:

Reichardt 2021

SCRIPT: https://bitbucket.org/rctirthankar/script/src/master/

R21:

Reichardt 2021

Lindsay Ng Lowry llowry1@berkeley.edu

Postdoc at UC Berkeley since Sept 2021, working with Adrian Lee

Deployment and Commissioning of POLARBEAR-2b (PB-2b)

• PB-2b is the second receiver of the Simons Array CMB experiment in Chile and was installed at the site in July 2022
• Worked as a graduate student at UCSD to build up PB-2b and prepare the site for its deployment
• As a postdoc, was involved in assembling and installing PB-2b at the site
• Now working to fully commission PB-2b, including optimizing and evaluating its sensitivity, and to determine the best observation strategy for doing science

Other Work

• Involved in laboratory detector testing for CMB-S4 and other experiments for which the UCB group does fabrication
• Interested in public outreach, and have been facilitating a “Scientist Pen-Pals” program with a local elementary school

Map courtesy of Megan Russell

Jason (Jaemyoung) Lee (4th year PhD student, SN Ia cosmology + LSS)

Email: astjason@sas.upenn.edu

Non-Gaussianity of the CIB & Its Gravitational Lensing

Poster Outside!

Lensing increases power spectra by 1 ~ 2% but (equilateral) bispectra by 10 ~ 20%!

Methods

Results

Inference of dust emissivity with Planck & HI data

Shabbir Shaikh (sshaik14@asu.edu)

• Debabrata Adak, SS, Tuhin Ghosh et al. in prep.

Planck data at 353 GHz

Data - Best-fit model

[I_Planck - CMB_Planck ]_HFI = 𝝴* N_HI + Offset + CIB + [HI residual] + Noise_Inst

Signal (S)

Gaussian likelihood, Hamiltonian Monte Carlo sampling

Results with simulations

Mock Data = S + N

Best fit signal

residual

sims

Noise (N)

at 545 GHz

Difference between

inferred parameters & input parameters.

model

GASS survey

Emissivity [Nside 32]

data

Colin Hill (Columbia, remote)

work with Kristen Surrao (Columbia)

Cosmological Parameter Inference via Needlet�Internal Linear Combination (NILC)-Based Likelihood

to appear on arXiv

see also Surrao, Philcox, JCH (2023):

https://arxiv.org/abs/2302.05436

- Standard CMB parameter inference methods (Planck, ACT, SPT, BICEP/Keck) only use information in the auto- and cross-frequency power spectra. For non-Gaussian fields, this is sub-optimal. Can we do better, e.g., with a more optimal weighting scheme to mitigate foregrounds and upweight CMB-dominated modes?

- Consider the auto- and cross-component power spectra of NILC maps for all fields {p,q} in the sky model. These are automatically weighted optimally to mitigate foregrounds. We have derived an analytic expression for the NILC maps’ power spectra, via a MASTER-like technique:

- Applying this method to a toy model sky containing CMB, (highly amplified) tSZ, and CMB-S4-like noise, we find ~10x improvement in parameter constraints:

- Potentially powerful application: primordial B-mode constraints

Astrophysical foreground cleanup using non-local means

Guillermo F. Quispe Peña

3rd year PhD student

Simon Fraser University

gfq@sfu.ca

arXiv:2306.00211 - Guillermo F. Quispe Peña and Andrei V. Frolov

• The algorithm is substantially more effective than anything else we are aware of for non-Gaussian emission maps, realizing a factor of two gain in spectral signal to noise ratio without any apparent signal loss for Planck 353GHz dust maps.
• Impact of the noise reduction is more apparent for the astrophysical foreground maps, which have strong features the algorithm can use to separate signal from noise based on morphology only, without resorting to frequency dependence of emission.

Generalized non-local means:

Feature space:

Development of DAQ Software & Critical Site Capabilities for the Simons Observatory

Develop critical site software: cooling loop flow & temp, thermometry, PWV, site power distribution, star cameras

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Developed housekeeping SQL db & HK analysis tools for providing simultaneous + immediate detector + HK analysis on-site & in analysis pipeline

Pipeline Tools

Sanah Bhimani (she/her)

(sun-nuh bee-mah-nee)

5th year, Newburgh Lab @ Yale

sanah.bhimani@yale.edu

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DAQ (OCS) Dev

Thermometry

Constructed/calibrated ~280 thermometers to map SO’s detector fluctuations

Next: Go Back to Chile + SO Early Data Analysis

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• Commissioning detector analysis: flags/cuts
• Leading the PWV + detector responsivity analysis
• Initial Science Observation pipeline work

2018

Thermometry

March 2023

Chile Site Network Setup

Hamza El Bouhargani

Postdoc at Berkeley Lab

working w/ Reijo Keskitalo, Julian Borrill

elbouha@lbl.gov

Reconstructing the first Planck submm polarization maps

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• 545GHz & 857GHz SWB detectors with residual polarization sensitivity of ~ few %
• Reprocessing data with an upgraded version of the NPIPE pipeline
• Improving ground calibration from in-flight and external data
• Modeling and mitigation of systematics, e.g., far sidelobes (FSL)

Secondary spillover

Baffle spillover

Primary spillover

Best-fit estimate of the far sidelobes beam

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857GHz polarization maps before/after FSL processing

Baseline

FSL corrected

Collaboration with: Reijo Keskitalo, Brandon Hensley, Aurelien Fraisse, Julian Borrill

Main beam

Zoomed-in Chamaeleon-Musca region 12x12 deg

galactic coordinates: (lon, lat) = (300, -13)

353GHz

857GHz

Paul Williams (Lawrence Berkeley National Lab)

• Postdoc working with Akito Kusaka
• I’m working on the design for the SAT Cryostats
• Prototype Cryostat I&T Plan
• Housekeeping Design
• Composite Materials Properties at Cryogenic Temperatures
• Also integrating SO SAT Cryostat at Berkeley Lab
• Shipping to Chile in about a month

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