Do Wave Functions Jump - Perspectives of the Work of GianCarlo Ghirardi

Preface
Contents
History and Honour
GianCarlo Ghirardi: Passing the Torch on Collapse Models
References
EPR-Bell-Schrödinger Proof of Nonlocality Using Position and Momentum
1 Introduction
2 Proof of Nonlocality Based on Perfect Correlations
2.1 Maximally Entangled States
2.2 Schrödinger's ``Theorem''
2.3 The Non-existence of Non-contextual Value-Maps
2.4 Nonlocality
3 The Original EPR Argument
3.1 EPR's General Setup
3.2 The Example of Position and Momentum
3.3 The Conclusions of the EPR Paper by EPR
3.4 The Conclusions of the EPR Paper by Einstein
3.5 Schrödinger's Extension of EPR
3.6 A Regularized EPR State
4 Proof of Nonlocality Using the EPR Variables
5 What Happens in Bohmian Mechanics?
5.1 The Measurement of Momentum in Bohmian Mechanics
5.2 The Contextuality of the Momentum Measurements in Bohmian Mechanics
5.3 An Example of Nonlocality in Bohmian Mechanics
6 Summary and Conclusions
References
Typicality in the Foundations of Statistical Physics and Born's Rule
1 Why ``Most'' Cannot Be Avoided
2 Born's Rule
3 Dynamical Relaxation?
4 Physically Misguided?
References
Presentation of Collapse Models
1 Modified Schrödinger Dynamics
2 The Continuos Spontaneous Localisations Model
2.1 Localisation of Macroscopic Objects
2.2 Extensions of the CSL Model
3 Other Collapse Models
References
Appreciating What He Did
1 The Second Innovation
Philosophy
The GRW Theory and the Foundations of Statistical Mechanics
Reference
Spontaneous Localization Theories with a Particle Ontology
1 Introduction
2 The Traditional Problem of Realism and Quantum Mechanics
3 The Real Trouble for the Quantum Realist
4 Different Ontologies for Different Theories
5 A Particle Ontology for Spontaneous Localization Theories
6 Comparison Among GRW-like Theories: Relativistic GRWp?
7 Conclusion
References
From the Measurement Problem to the Primitive Ontology Programme
1 The Measurement Problem and the Ontology of Quantum Physics
2 The Ontology of GRW I: Matter Density Field
3 The Ontology of GRW II: Flashes
4 The Status of the Wave Function: Dynamics, not Ontology
References
Might Laws of Nature ‘Ground’ Phenomena?
1 Introduction
2 Grounding: A Nomological Reading?
3 Laws of Nature: Governing Versus Non-Governing Answers
4 Laws as Primitives
5 Laws as Grounding Items?
References
On Closing the Circle
1 Introduction
2 How not to Close the Circle
3 Closing the Circle with Quantum Jumps
4 Primitive Ontology
5 Wave Function as Structure
6 Closing the Circle—and Opening Another
7 Conclusion
References
Mathematical Physics
On the Complete Positivity of the Ghirardi-Rimini-Weber Model
1 Introduction
2 GRW-Model
3 Explicit Solution to the Generalized GRW Model
3.1 Solution in the Heisenberg Picture
4 Complete Positivity of the Generalized GRW Model
4.1 Standard GRW Model for a Free Particle
4.2 Generalized GRW Model for a Free Particle: Singular Rate Function
4.3 Generalized GRW Model for a Free Particle: Small α Limit
5 Conclusions
References
Energy-Lifetime Relations
1 Introduction
2 Gamow's Model of Alpha Decay and Skibsted's Variation of It
3 The Energy Time Uncertainty Relation and the Linewidth-Lifetime Relation Are Different
4 Conclusion
References
On the Continuum Limit of the GRW Model
1 Discrete and Continuous Collapse Models
2 The Linear Structure Behind the GRW Model
3 The Continuum Limit of GRW and the Stochastic Trotter Formula
4 Giancarlo Ghirardi
References
Continuous Collapse Models on Finite Dimensional Hilbert Spaces
1 Setup
1.1 The Stochastic Schrödinger Equation and Its Origin
1.2 The Stochastic Master Equation
2 Pure Collapse
3 Jumps
3.1 Qubit with Dissipative Dynamics
3.2 Qubit with Coherent Dynamics
3.3 General Case
4 Spikes
4.1 A First Observation
4.2 Martingale Intuition
4.3 Sketch of a Proof
4.4 Are Spikes Real?
5 Generalization and Open Problems
6 Summary and Conclusion
References
Theoretical Physics
Collapse Models, Relativity, and Discrete Spacetime
1 Introduction
2 Collapses Are Like Measurements
3 Constructing a Relativistic Collapse Model
4 Discrete Spacetime, Quantum Fields, and Collapses
5 Discussion
References
Opto-Mechanical Test of Collapse Models
1 Non-interferometric Experiments: A New Perspective in Collapse Model Testing
2 Opto-Mechanical System as a Probe of the Collapse Mechanism
3 Experimental Bounds
4 Testing of the Dissipative and Colored CSL Models
5 Proposals for Future Testing
References
Two Invariant Surface-Tensors Determine CSL of Massive Body Wave Function
1 Introduction
2 Center-of-mass Decoherence
3 Invariant Surface-Tensor for C.O.M. Decoherence
4 Rotational Decoherence
5 Outlines of Generalizations
6 Concluding Remarks
References
Collapse and Charged Particles
1 Introduction
2 First Calculations of the Collapse-Induced Radiation Emission
3 Comparison with the Experimental Data
4 A Discrepancy Among Different Calculations of the Emission Rate
5 Repeating the Perturbative Calculation with the CSL Model
6 An Exact Analysis with the Non-Markovian QMUPL
7 Getting the Correct Result in the CSL Model
8 Conclusions and Perspectives
References
Relativistic Quantum Theory
1 Topics to Be Addressed
2 Why Are We Not Able to Predict the Future by Using Our Physical Theories, and Why Is Quantum Theory Intrinsically Probabilistic?
3 The Meaning of ``Locality'' or ``Einstein Causality'' in Relativistic Quantum Theory
4 Relativistic Quantum Theory, and the Notion of ``events''
5 Monitoring Events by Measuring Physical Quantities
6 Conclusions and Outlook
References
Classically Gravitating Quantum Systems
1 Introduction
2 Semiclassical Gravity in the Nonrelativistic Limit
2.1 Composite Systems
3 Entanglement Generation Through Newtonian Gravity
4 Is Semiclassical Gravity Causally Consistent?
References
Collapse Models and Cosmology
1 Introduction
2 Cosmic Inflation and Cosmological Perturbations
3 Motivations
4 Inflation and Collapse
5 Comparison with Observations
6 Conclusions
References
Spontaneous Collapse Theories and Cosmology
1 Introduction
2 Cosmological Inflationary Model
2.1 The Standard Treatment
3 The Case for a Modified Approach and a Specific Proposal
3.1 Conceptual Difficulties in the Standard Approach
3.2 Spontaneous Collapse of the Quantum State and Einstein's Semi-classical Equations
4 Practical Treatment Adapted to the Cosmological Setting
4.1 Primordial Gravity Waves
5 Discussion
References
A Relativistic GRW Flash Process with Interaction
1 Introduction
2 Review of the Non-interacting Version
3 Assumptions
4 Interacting Model
4.1 A Simple Case
4.2 General Case
5 Properties of the Model
References
Non-Markov Processes in Quantum Theory
1 Introduction
2 Open Systems and Quantum Processes
3 Events and Decoherence
4 Non-Markovian Processes
5 Conclusions and Outlook
References
Experimental Physics
Eight Oxford Questions: Quantum Mechanics Under a New Light
1 Background
2 The Questions
3 Discussion and Conclusions
References
Interferometric Tests of Wave-Function Collapse
1 How the Puzzle Started
2 Experimental Approaches to Testing Objective Collapse
2.1 Far-Field Diffraction
2.2 Near Field Interference with a Long Baseline Interferometer
3 A Look into the Future of Matter-Wave Tests of CSL Models
4 Summary: On the Distinction of Collapse and Decoherence
References
Tests in Space
1 Beyond State of the Art
2 Why Space?
3 MAQRO—Macroscopic Quantum Resonators
4 QPPF—A Quantum Physics Platform in Space
5 The Experiments to Be Performed
6 Using the Results to Test Quantum Physics
7 Recent Results and Current Efforts
8 The Next Steps Towards Experiments in Space
9 Conclusions
References
Sneaking a Look at Ghirardi's Cards: Collapse Models Mapped with the Spontaneous Radiation
1 Introduction
2 Collapse Models and Characteristic Physical Parameters
3 Recent Upper Limits on λ from Spontaneous Radiation Search
4 Ongoing Experimental Efforts and Future Perspectives
References
New Avenues for Testing Collapse Models
1 Introduction
2 Noninterferometric Mechanical Tests of Collapse Models
2.1 Key Concepts
2.2 Cantilevers and Other Clamped Resonators
2.3 Levitated Particles
3 Bulk Heating Experiments
4 Cold Atoms and Condensates
5 Matter-Wave Interferometry
6 Some Concluding Remarks
References