scholarly journals Testing Fundamental Physics by Using Levitated Mechanical Systems

2021 ◽  
pp. 303-332
Author(s):  
Hendrik Ulbricht
Keyword(s):  
Dark Matter ◽  
Quantum Mechanics ◽  
Recent Progress ◽  
Large Mass ◽  
Mass Motion ◽  
Quantum Superposition ◽  
Frankfurt Am Main ◽  
Fundamental Physics ◽  
Foundations Of Physics ◽  
Physical Effects

AbstractWe will describe recent progress of experiments towards realising large-mass single particle experiments to test fundamental physics theories such as quantum mechanics and gravity, but also specific candidates of Dark Matter and Dark Energy. We will highlight the connection to the work started by Otto Stern as levitated mechanics experiments are about controlling the centre of mass motion of massive particles and using the same to investigate physical effects. This chapter originated from the foundations of physics session of the Otto Stern Fest at Frankfurt am Main in 2019, so we will also share a view on the Stern Gerlach experiment and how it related to tests of the principle of quantum superposition.

scholarly journals Approaching the motional ground state of a 10-kg object

Science ◽  
2021 ◽  
Vol 372 (6548) ◽  
pp. 1333-1336
Author(s):  
Chris Whittle ◽  
Evan D. Hall ◽  
Sheila Dwyer ◽  
Nergis Mavalvala ◽  
Vivishek Sudhir ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Ground State ◽  
Room Temperature ◽  
Thermal Environment ◽  
Center Of Mass ◽  
Large Mass ◽  
Quantum Systems ◽  
Mass Motion ◽  
Mechanical Object ◽  
Magnitude Increase

The motion of a mechanical object, even a human-sized object, should be governed by the rules of quantum mechanics. Coaxing them into a quantum state is, however, difficult because the thermal environment masks any quantum signature of the object’s motion. The thermal environment also masks the effects of proposed modifications of quantum mechanics at large mass scales. We prepared the center-of-mass motion of a 10-kilogram mechanical oscillator in a state with an average phonon occupation of 10.8. The reduction in temperature, from room temperature to 77 nanokelvin, is commensurate with an 11 orders-of-magnitude suppression of quantum back-action by feedback and a 13 orders-of-magnitude increase in the mass of an object prepared close to its motional ground state. Our approach will enable the possibility of probing gravity on massive quantum systems.

Relational Blockworld and Quantum Mechanics

2018 ◽  
Author(s):  
Michael Silberstein ◽  
W.M. Stuckey ◽  
Timothy McDevitt
Keyword(s):  
Quantum Mechanics ◽  
Measurement Problem ◽  
Quantum Nonlocality ◽  
Global Constraints ◽  
Quantum Superposition ◽  
Delayed Choice ◽  
Counterfactual Definiteness ◽  
Main Thread ◽  
Block Universe ◽  
Contextual Emergence

The main thread of chapter 4 introduces some of the major mysteries and interpretational issues of quantum mechanics (QM). These mysteries and issues include: quantum superposition, quantum nonlocality, Bell’s inequality, entanglement, delayed choice, the measurement problem, and the lack of counterfactual definiteness. All these mysteries and interpretational issues of QM result from dynamical explanation in the mechanical universe and are dispatched using the authors’ adynamical explanation in the block universe, called Relational Blockworld (RBW). A possible link between RBW and quantum information theory is provided. The metaphysical underpinnings of RBW, such as contextual emergence, spatiotemporal ontological contextuality, and adynamical global constraints, are provided in Philosophy of Physics for Chapter 4. That is also where RBW is situated with respect to retrocausal accounts and it is shown that RBW is a realist, psi-epistemic account of QM. All the relevant formalism for this chapter is provided in Foundational Physics for Chapter 4.

scholarly journals On Russell’s 1927 Book The Analysis of Matter

Philosophies ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 40
Author(s):  
Said Mikki
Keyword(s):  
General Relativity ◽  
Quantum Mechanics ◽  
Building Blocks ◽  
Bertrand Russell ◽  
Important Work ◽  
Philosophy Of Nature ◽  
Foundations Of Physics ◽  
The World ◽  
Ordinal Space ◽  
Historical Fact

The goal of this article is to bring into wider attention the often neglected important work by Bertrand Russell on the philosophy of nature and the foundations of physics, published in the year 1927. It is suggested that the idea of what could be named Russell space, introduced in Part III of that book, may be viewed as more fundamental than many other types of spaces since the highly abstract nature of the topological ordinal space proposed by Russell there would incorporate into its very fabric the emergent nature of spacetime by deploying event assemblages, but not spacetime or particles, as the fundamental building blocks of the world. We also point out the curious historical fact that the book The Analysis of Matter can be chronologically considered the earliest book-length generic attempt to reflect on the relation between quantum mechanics, just emerging by that time, and general relativity.

scholarly journals Dark matter and fundamental physics with the Cherenkov Telescope Array

2013 ◽  
Vol 43 ◽  
pp. 189-214 ◽  
Author(s):  
M. Doro ◽  
J. Conrad ◽  
D. Emmanoulopoulos ◽  
M.A. Sànchez-Conde ◽  
J.A. Barrio ◽  
...  
Keyword(s):  
Dark Matter ◽  
Fundamental Physics ◽  
Telescope Array ◽  
Cherenkov Telescope

A Tale of Two Infinities

2021 ◽  
Author(s):  
Gianfranco Bertone
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Gravitational Waves ◽  
Direct Detection ◽  
Traditional Approach ◽  
Fundamental Physics ◽  
Modern Cosmology ◽  
Nobel Prize In Physics ◽  
The Universe ◽  
Modern Astronomy

The spectacular advances of modern astronomy have opened our horizon on an unexpected cosmos: a dark, mysterious Universe, populated by enigmatic entities we know very little about, like black holes, or nothing at all, like dark matter and dark energy. In this book, I discuss how the rise of a new discipline dubbed multimessenger astronomy is bringing about a revolution in our understanding of the cosmos, by combining the traditional approach based on the observation of light from celestial objects, with a new one based on other ‘messengers’—such as gravitational waves, neutrinos, and cosmic rays—that carry information from otherwise inaccessible corners of the Universe. Much has been written about the extraordinary potential of this new discipline, since the 2017 Nobel Prize in physics was awarded for the direct detection of gravitational waves. But here I will take a different angle and explore how gravitational waves and other messengers might help us break the stalemate that has been plaguing fundamental physics for four decades, and to consolidate the foundations of modern cosmology.

scholarly journals A multi-component SIMP model with U(1)X → Z2 × Z3

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Soo-Min Choi ◽  
Jinsu Kim ◽  
Pyungwon Ko ◽  
Jinmian Li
Keyword(s):  
Dark Matter ◽  
Gauge Symmetry ◽  
Mass Difference ◽  
Massive Particle ◽  
Large Mass ◽  
Small Mass ◽  
Dark Matter Candidate ◽  
Mass Hierarchy ◽  
New Class ◽  
Matter Fields

Abstract Multi-component dark matter scenarios are studied in the model with U(1)X dark gauge symmetry that is broken into its product subgroup Z2 × Z3 á la Krauss-Wilczek mechanism. In this setup, there exist two types of dark matter fields, X and Y, distinguished by different Z2 × Z3 charges. The real and imaginary parts of the Z2-charged field, XR and XI, get different masses from the U(1)X symmetry breaking. The field Y, which is another dark matter candidate due to the unbroken Z3 symmetry, belongs to the Strongly Interacting Massive Particle (SIMP)-type dark matter. Both XI and XR may contribute to Y’s 3 → 2 annihilation processes, opening a new class of SIMP models with a local dark gauge symmetry. Depending on the mass difference between XI and XR, we have either two-component or three-component dark matter scenarios. In particular two- or three-component SIMP scenarios can be realised not only for small mass difference between X and Y, but also for large mass hierarchy between them, which is a new and unique feature of the present model. We consider both theoretical and experimental constraints, and present four case studies of the multi-component dark matter scenarios.

scholarly journals The Search for Feebly Interacting Particles

2021 ◽  
Vol 71 (1) ◽  
pp. 279-313
Author(s):  
Gaia Lanfranchi ◽  
Maxim Pospelov ◽  
Philip Schuster
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Interaction Strength ◽  
New Physics ◽  
Fine Tuning ◽  
Experimental Program ◽  
Interacting Particles ◽  
Fundamental Physics ◽  
The Standard Model ◽  
The Universe

At the dawn of a new decade, particle physics faces the challenge of explaining the mystery of dark matter, the origin of matter over antimatter in the Universe, the apparent fine-tuning of the electroweak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves New Physics at mass scales comparable to that of familiar matter—below the GeV scale but with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and existing data may even provide hints of this possibility. Emboldened by the lessons of the LHC, a vibrant experimental program to discover such physics is underway, guided by a systematic theoretical approach that is firmly grounded in the underlying principles of the Standard Model. We give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs, and we focus in particular on accelerator-based experiments.

Philosophy of Physics: A Very Short Introduction

2021 ◽  
Author(s):  
David Wallace
Keyword(s):  
Quantum Mechanics ◽  
Scientific Method ◽  
Philosophy Of Physics ◽  
Short Introduction ◽  
Fundamental Physics ◽  
The Core ◽  
The World ◽  
Modern Physics ◽  
Parallel Universes ◽  
Large Systems

Philosophy of Physics: A Very Short Introduction explores the core topics of philosophy of physics through three key themes: the nature of space and time; the origin of irreversibility and probability in the physics of large systems; how we can make sense of quantum mechanics. Central issues discussed include: the scientific method as it applies in modern physics; the distinction between absolute and relative motion; the way that distinction changes between Newton’s physics and special relativity; what spacetime is and how it relates to the laws of physics; how fundamental physics can make no distinction between past and future and yet a clear distinction exists in the world we see around us; why it is so difficult to understand quantum mechanics, and why doing so might push us to change our fundamental physics, to rethink the nature of science, or even to accept the existence of parallel universes.

Quantum mechanics, interpretation of

2018 ◽  
Author(s):  
Allen Stairs
Keyword(s):  
Quantum Mechanics ◽  
Microscopic Level ◽  
Quantum States ◽  
Quantum Mechanical ◽  
Quantum Superposition ◽  
Ordinary Objects ◽  
Making Sense ◽  
Interpretations Of Quantum Mechanics ◽  
The World

Quantum mechanics developed in the early part of the twentieth century in response to the discovery that energy is quantized, that is, comes in discrete units. At the microscopic level this leads to odd phenomena: light displays particle-like characteristics and particles such as electrons produce wave-like interference patterns. At the level of ordinary objects such effects are usually not evident, but this generalization is subject to striking exceptions and puzzling ambiguities. The fundamental quantum mechanical puzzle is ’superposition of states’. Quantum states can be added together in a manner that recalls the superposition of waves, but the effects of quantum superposition show up only probabilistically in the statistics of many measurements. The details suggest that the world is indefinite in odd ways; for example, that things may not always have well-defined positions or momenta or energies. However, if we accept this conclusion, we have difficulty making sense of such straightforward facts as that measurements have definite results. Interpretations of quantum mechanics are, in one way or another, attempts to understand the superposition of quantum states. The range of interpretations stretches from the metaphysically daring to the seemingly innocuous. But, so far, no single interpretation has commanded anything like universal agreement.

scholarly journals Development of a space cold atom clock

2020 ◽  
Vol 7 (12) ◽  
pp. 1828-1836
Author(s):  
Wei Ren ◽  
Tang Li ◽  
Qiuzhi Qu ◽  
Bin Wang ◽  
Lin Li ◽  
...  
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Cold Atoms ◽  
Cold Atom ◽  
Deep Space ◽  
Fundamental Physics ◽  
Time Frequency ◽  
Frequency Standards ◽  
Scientific Experiments ◽  
Primary Frequency

Abstract Atomic clocks with cold atoms play important roles in the field of fundamental physics as well as primary frequency standards. Operating such cold atom clocks in space paves the way for further exploration in fundamental physics, for example dark matter and general relativity. We developed a space cold atom clock (SCAC), which was launched into orbit with the Space Lab TG-2 in 2016. Before it deorbited with TG-2 in 2019, the SCAC had been working continuously for almost 3 years. During the period in orbit, many scientific experiments and engineering tests were performed. In this article, we summarize the principle, development and in-orbit results. These works provide the basis for construction of a space-borne time-frequency system in deep space.

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