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giulianp@frib.msu.edu

Pablo Giuliani

Beyond projections:

Learning Equations from Data

Other brands

Dimensionality

reduction

ASCSN

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Outline

2

My current MOR perspective

Reduced Coordinates and Reduced Equations

Ask questions

Equations from data

Gain and Pain

Questions and Challenges for our field

What’s out there?

Our approaches

Conclusions

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Conclusions

2

1) I believe we could streamline the creation of reduced order models for nuclear physics

Structure

Astrophysics

Symmetries

Applications

Th.

Exp.

2) I believe mastering “learning equations from data” is going to be key

3) I believe we should invest in thermalizing with the state of the art of model order reduction

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How it works

4

Parameters:

Density Functional Theory

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How it works

5

Parameters:

Density Functional Theory

(Binding Energy)

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How it works

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Density Functional Theory

Parameters:

(Binding Energy)

.

.

.

.

.

.

~5000 variables

High Fidelity

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How it works

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Density Functional Theory

Parameters:

(Binding Energy)

.

.

.

.

.

.

~5000 variables

~50 variables

Reduced

Model

High Fidelity

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How it works

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Density Functional Theory

Parameters:

(Binding Energy)

.

.

.

.

.

.

~5000 variables

~50 variables

Reduced Model

High Fidelity

Reduced

Model

High Fidelity

CAT plot

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How it works

“High Fidelity”

“Emulated”

Physical model

Posterior distribution

Gaussian Process

Neural Networks

Model Order Reduction:

Variational Bayes

Chaos expansion

Normalizing flows

Reduced basis methods

(~eigenvector continuation)

Dynamic Mode Decomposition

SINDy and NIF

…

…

…

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How it works

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1) Find good reduced coordinates

2) Find equations for them

Reducing your model in two easy steps:

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How it works

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1) Find good reduced coordinates

2) Find equations for them

Reducing your model in two easy steps:

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How it works

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3 translations

3 rotations

+

1) Find good reduced coordinates

2) Find equations for them

Reducing your model in two easy steps:

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How it works

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3 translations

3 rotations

+

1) Find good reduced coordinates

2) Find equations for them

Reducing your model in two easy steps:

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How it works

Quantum Harmonic Oscillator

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How it works

Quantum Harmonic Oscillator

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How it works

Quantum Harmonic Oscillator

.

.

.

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How it works

Quantum Harmonic Oscillator

.

.

.

Long vector

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How it works

Quantum Harmonic Oscillator

Many Long vectors

Solution Manifold

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How it works

Quantum Harmonic Oscillator

Solution Manifold

Reduced space

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How it works

Quantum Harmonic Oscillator

.

.

.

Dimension

n

Solution Manifold

Reduced space

>>

(300)

(2)

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How it works

Quantum Harmonic Oscillator

.

.

.

Dimension

n

Solution Manifold

Reduced space

>>

(300)

(2)

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How it works

Quantum Harmonic Oscillator

Reduced Basis

PCA

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How it works

Quantum Harmonic Oscillator

Reduced Basis

PCA

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How it works

Quantum Harmonic Oscillator

Reduced Basis

PCA

Boris Galerkin

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How it works

Quantum Harmonic Oscillator

Reduced Basis

PCA

Boris Galerkin

Two coefficients

​

Two equations

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How it works

Reducing your model in two easy steps:

2) Find equations for them

Reduced Basis Method

One equation per coefficient

Principal Component

Analysis

1) Find good reduced coordinates

Harmonic Oscillator Example

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How it works

Reduced Basis Method

Linear Embedding

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How it works

Reduced Basis Method

Linear Embedding

Good

Bad

PCA Doctor

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Gain and Pain

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Gain and Pain

Skyrme DFT

RMF DFT

Scattering

Time dynamics

AFDMC

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Gain and Pain

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Harmonic Oscillator Example

All is easy

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Gain and Pain

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Harmonic Oscillator Example

All is easy

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Skyrme DFT

VERY non-linear

Harmonic Oscillator Example

All is easy

Gain and Pain

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Skyrme DFT

VERY non-linear

Toy model:

Harmonic Oscillator Example

All is easy

Gain and Pain

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Relativistic Mean Fields

Harmonic Oscillator Example

All is easy

Gain and Pain

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Relativistic Mean Fields

Harmonic Oscillator Example

All is easy

Gain and Pain

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Gain and Pain

Harmonic Oscillator Example

All is easy

Relativistic Mean Fields

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Gain and Pain

Harmonic Oscillator Example

All is easy

Relativistic Mean Fields

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Gain and Pain

Harmonic Oscillator Example

All is easy

Relativistic Mean Fields

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Scattering

Harmonic Oscillator Example

All is easy

Gain and Pain

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Scattering

Empirical Interpolation Method

Harmonic Oscillator Example

All is easy

Gain and Pain

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Gain and Pain

Harmonic Oscillator Example

All is easy

Scattering

Empirical Interpolation Method

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Two more “issues”

Harmonic Oscillator Example

All is easy

Experimental control

Singular Values

Components k

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Two more “issues”

Harmonic Oscillator Example

All is easy

Experimental control

Singular Values

Components k

?

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Two more “issues”

Harmonic Oscillator Example

All is easy

Extended Reduced Coordinates

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Two more “issues”

Harmonic Oscillator Example

All is easy

Extended Reduced Coordinates

.

.

.

.

.

.

.

.

.

.

.

.

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Equations from Data

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Our approaches

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Equations from Data

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Vintage Galerkin

Our approaches

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Equations from Data

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Vintage Galerkin

Our approaches

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Equations from Data

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Learn Equations from data

Fit from data

Vintage Galerkin

Black-box Galerkin

Our approaches

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Equations from Data

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Learn Equations from data

Fit from data

Vintage Galerkin

Black-box Galerkin

Our approaches

Closer to non-linear embedding

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Equations from Data

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Learn Equations from data

Fit from data

Vintage Galerkin

Black-box Galerkin

Danny Jammooa

Daniel Lee

Dean Lee

Patrick Cook

Morten Hjorth-Jensen

https://arxiv.org/abs/2401.11694

Fit from data

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Equations from Data

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Learn Equations from data

Fit from data

Vintage Galerkin

Black-box Galerkin

Danny Jammooa

Daniel Lee

Dean Lee

Patrick Cook

Morten Hjorth-Jensen

https://arxiv.org/abs/2401.11694

Very different application

Fit from data

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Equations from Data

Inefficient

Our approaches

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Equations from Data

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Learn Equations from data

~ 3,000 faster than high fidelity

Inefficient

Our approaches

Edgard B.

Ruchi G.

Diogenes F.

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Equations from Data

Our approaches

Casey

Ingo

Rahul

Stefano

Kyle

LANL team

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Equations from Data

Equation

Of

State

Our approaches

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Equations from Data

Equation

Of

State

Our approaches

Brendan Reed

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Equations from Data

Equation

Of

State

Predictors

Our approaches

Brendan Reed

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Brendan Reed

Brendan Reed

Equation

Of

State

Predictors

This is what I meant by inefficient

Our approaches

Equations from Data

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Equations from Data

Equation

Of

State

Predictors

This is what I meant by inefficient

Our approaches

That’s how ROSE works!

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Equations from Data

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What’s out there?

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Equations from Data

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What’s out there?

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Equations from Data

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What’s out there?

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Equations from Data

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What’s out there?

A lot

Like, a lot a lot

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Equations from Data

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What’s out there?

A lot

Like, a lot a lot

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Questions and challenges

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What’s out there?

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Questions and challenges

68

What’s out there?

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Questions and challenges

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What’s out there?

Awesome stuff we have done!

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Questions and challenges

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What’s out there?

MOR Technology from 2004

Awesome stuff we have done!

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Questions and challenges

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What’s out there?

Big part of my contribution to physics

MOR Technology from 2004

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Questions and challenges

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What’s out there?

Why these work?

Fit from data

PMM

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Questions and challenges

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What’s out there?

Why these work?

Fit from data

PMM

Right tool for the right job

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Questions and challenges

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What’s out there?

Why these work?

Fit from data

PMM

Right tool for the right job

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Questions and challenges

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What’s out there?

Why these work?

Fit from data

PMM

Right tool for the right job

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Questions and challenges

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What’s out there?

Why these work?

Fit from data

PMM

When and how they break?

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Questions and challenges

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What’s out there?

Why these work?

Fit from data

PMM

Casey

When and how they break?

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Questions and challenges

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What’s out there?

Why these work?

When and how they break?

What do we do from here?

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Questions and challenges

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What’s out there?

Why these work?

When and how they break?

What do we do from here?

ASCSN

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Conclusions

2

1) I believe we could streamline the creation of reduced order models for nuclear physics

Structure

Astrophysics

Symmetries

Applications

Th.

Exp.

2) I believe mastering “learning equations from data” is going to be key

3) I believe we should invest in thermalizing with the state of the art of model order reduction

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Further resources

81

Thank-yous

ASCSN Team

Jorge Piekarewicz

Frederi Viens

Kyle Godbey

Edgard Bonilla

Witek Nazarewicz

Dean Lee

Magda Kuich

Ana Posada

Moses Chan

Daniel Phillips

Eric Flynn

Daniel Odell

Daniel Lay

Filomena Nunes

Yanlai Chen

Aaron Phillip

Landon Buskirk

Dirac

Ruchi Garg

Ingo Twes

Kyle Beyer

Amy Anderson

And thank you,

for listening

People who pay

my lunch and collaborations

Diogenes Figueroa

Friends & collaborators

Manuel Catacora-Rios

Yukari Yamauchi

Dick Furnstahl

Ágnes Mócsy

Brendan Reed

Alexandra Semposki

…

http://databookuw.com/

https://dr.ascsn.net

Amy Lovell

https://forum.ascsn.net/t/about-the-2023-frib-ta-summer-school/42

Michelle Kuchera

Vojta Kejzlar

Ruoyu Cheng

Link to slides

Sudhanva Lalit

Megan Campbell

Chloe Hebborn

giulianp@

frib.msu.edu

Cassandra Armstrong

Rahul Somasundaram

Stefano Gandolf

Christian Drischler

Patrick Cook

Danny Jammooa