scholarly journals A measurement of the cosmic expansion within our lifetime

2021 ◽  
Author(s):  
Fulvio Melia
Keyword(s):  
Standard Model ◽  
Cosmological Constant ◽  
Physical Properties ◽  
Particle Physics ◽  
The Other ◽  
Model Parameters ◽  
Cosmic Expansion ◽  
Redshift Drift ◽  
The Standard Model ◽  
The Universe

Abstract The most exciting future observation in cosmology will feature a monitoring of the cosmic expansion in real time, unlike anything that has ever been attempted before. This campaign will uncover crucial physical properties of the various constituents in the Universe, and perhaps answer a simpler question concerning whether or not the cosmic expansion is even accelerating. An unambiguous yes/no response to this query will significantly impact cosmology, of course, but also the standard model of particle physics. Here, we discuss---in a straightforward way---how to understand the so-called `redshift drift' sought by this campaign, and why its measurement will help us refine the standard-model parameters if the answer is `yes.' A `no' answer, on the other hand, could be more revolutionary, in the sense that it might provide a resolution of several long-standing problems and inconsistencies in our current cosmological models. An outcome of zero redshift drift, for example, would obviate the need for a cosmological constant and render inflation completely redundant.

scholarly journals ℋolographic 𝒩aturalness

2020 ◽  
Vol 29 (14) ◽  
pp. 2050084
Author(s):  
Andrea Addazi
Keyword(s):  
Standard Model ◽  
Cosmological Constant ◽  
Particle Physics ◽  
Intrinsic Disorder ◽  
High Energy ◽  
Holographic Principle ◽  
New Paradigm ◽  
The Standard Model ◽  
The Universe ◽  
Decoherence Effect

The [Formula: see text]olographic [Formula: see text]aturalness ([Formula: see text]) is a new paradigm towards an explanation of the Cosmological Constant (CC) and the Higgs Hierarchy (HH) in the Universe. Motivated by the Holographic Principle, and inspired by the (A)dS/CFT correspondence, we elaborate on the possibility and on the cosmological consequences of a fundamental intrinsic disorder and temperature in vacuo. We postulate that the zero vacuum entropy is provided by a large number of quantum hair fields, the hairons. The quantum hairon gas in spacetime induces an effective decoherence effect to the Standard Model (SM) particle sector. This is leading to an entropic reinterpretation of UV divergent contributions to CC and HH: we will show that, in both the cases, the large number of re-scatterings on the hairon ensamble suppresses any radiative instabilities. The CC and HH problems are illusions envisaged by a conscious observer, having access on the limited amount of information from SM tests: both the issues are originated from our ignorance of the hidden entropy intrinsically stored in the spacetime. The [Formula: see text] suggests to search for effective decoherence effects in particle physics observables such as effective CPT, Unitarity and Energy violations. Regarding the HH, the [Formula: see text] does not introduce any new particles or interactions around the TeV-scale: we do not expect for any signatures, at LHC and any future high energy colliders, related to the Higgs UV completion in a Wilsonian sense.

An Interview with the Physicist that Her Head in the Universe and Both Feet on the Earth

2019 ◽  
Author(s):  
Adib Rifqi Setiawan
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
Space Time ◽  
Additional Dimension ◽  
The Earth ◽  
The Standard Model ◽  
The Universe

Put simply, Lisa Randall’s job is to figure out how the universe works, and what it’s made of. Her contributions to theoretical particle physics include two models of space-time that bear her name. The first Randall–Sundrum model addressed a problem with the Standard Model of the universe, and the second concerned the possibility of a warped additional dimension of space. In this work, we caught up with Randall to talk about why she chose a career in physics, where she finds inspiration, and what advice she’d offer budding physicists. This article has been edited for clarity. My favourite quote in this interview is, “Figure out what you enjoy, what your talents are, and what you’re most curious to learn about.” If you insterest in her work, you can contact her on Twitter @lirarandall.

An Interview with the Physicist that Her Head in the Universe and Both Feet on the Earth

2019 ◽  
Author(s):  
Adib Rifqi Setiawan
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
Space Time ◽  
Additional Dimension ◽  
The Earth ◽  
The Standard Model ◽  
The Universe

Put simply, Lisa Randall’s job is to figure out how the universe works, and what it’s made of. Her contributions to theoretical particle physics include two models of space-time that bear her name. The first Randall–Sundrum model addressed a problem with the Standard Model of the universe, and the second concerned the possibility of a warped additional dimension of space. In this work, we caught up with Randall to talk about why she chose a career in physics, where she finds inspiration, and what advice she’d offer budding physicists. This article has been edited for clarity. My favourite quote in this interview is, “Figure out what you enjoy, what your talents are, and what you’re most curious to learn about.” If you insterest in her work, you can contact her on Twitter @lirarandall.

scholarly journals The force and gravity of events

2016 ◽  
Vol 31 (16) ◽  
pp. 1630015 ◽  
Author(s):  
Robert Delbourgo
Keyword(s):  
Standard Model ◽  
Cosmological Constant ◽  
Ricci Scalar ◽  
The Other ◽  
Gauge Fields ◽  
Generalized Metric ◽  
The Standard Model ◽  
Property Space

Local events are characterized by “where”, “when” and “what”. Just as (bosonic) spacetime forms the backdrop for location and time, (fermionic) property space can serve as the backdrop for the attributes of a system. With such a scenario I shall describe a scheme that is capable of unifying gravitation and the other forces of nature. The generalized metric contains the curvature of spacetime and property separately, with the gauge fields linking the bosonic and fermionic arenas. The super-Ricci scalar can then automatically yield the spacetime Lagrangian of gravitation and the Standard Model (plus a cosmological constant) upon integration over property coordinates.

scholarly journals HIGGS MASS FROM A CASIMIR ENERGY INDUCED COSMOLOGICAL CONSTANT IN THE STANDARD MODEL

2004 ◽  
Vol 19 (13n16) ◽  
pp. 1195-1201
Author(s):  
XIAO-GANG HE
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Cosmological Constant ◽  
Spontaneous Symmetry Breaking ◽  
Particle Physics ◽  
Higgs Mass ◽  
Vacuum Energy ◽  
Casimir Energy ◽  
Renormalization Scale ◽  
The Standard Model

Casimir vacuum energy is divergent. It needs to be regularized. The regularization introduces a renormalization scale which may lead to a scale dependent cosmological constant. We show that the requirement of physical cosmological constant is renormalization scale independent provides important constraints on possible particle contents and their masses in particle physics models. In the Standard Model of strong and electroweak interactions, besides the Casimir vacuum energy there is also vacuum energy induced from spontaneous symmetry breaking. The requirement that the total vacuum energy to be scale independent dictates the Higgs mass to be [Formula: see text] where the summation is over fermions and Ni equals to 3 and 1 for quarks and leptons, respectively. The Higgs mass is predicted to be approximately 382 GeV.

Particle physics today, tomorrow and beyond

2018 ◽  
Vol 33 (02) ◽  
pp. 1830003 ◽  
Author(s):  
John Ellis
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Particle Physics ◽  
Beyond The Standard Model ◽  
Visible Matter ◽  
The Standard Model ◽  
Cosmological Inflation ◽  
The Stability ◽  
The Universe ◽  
Lhc I

The most important discovery in particle physics in recent years was that of the Higgs boson, and much effort is continuing to measure its properties, which agree obstinately with the Standard Model, so far. However, there are many reasons to expect physics beyond the Standard Model, motivated by the stability of the electroweak vacuum, the existence of dark matter and the origin of the visible matter in the Universe, neutrino physics, the hierarchy of mass scales in physics, cosmological inflation and the need for a quantum theory for gravity. Most of these issues are being addressed by the experiments during Run 2 of the LHC, and supersymmetry could help resolve many of them. In addition to the prospects for the LHC, I also review briefly those for direct searches for dark matter and possible future colliders.

The Daya Bay Experiment and the Discovery of a New Type of Neutrino Oscillation

2012 ◽  
Vol 01 (02) ◽  
pp. 45-49
Author(s):  
Yifang Wang
Keyword(s):  
Standard Model ◽  
Experimental Evidence ◽  
Neutrino Oscillation ◽  
Particle Physics ◽  
Weak Interactions ◽  
Daya Bay ◽  
The Standard Model ◽  
New Type ◽  
Charged Leptons ◽  
The Universe

We know nowadays that the matter world we live in is made of 12 elementary particles, including 6 quarks, 3 charged leptons and 3 neutrinos. Among them, neutrinos are least known since they do not carry the electric charge and interact with others only weakly (often referred as the nuclear weak interactions). In the Standard Model of particle physics before 1998, neutrinos are considered as massless for simplicity and lack of experimental evidence. However, they are so abundant in the universe that their masses, even if tiny, will have significant impact to the particle physics, astrophysics and cosmology.

scholarly journals SMART U(1)$$_X$$: standard model with axion, right handed neutrinos, two Higgs doublets and U(1)$$_X$$ gauge symmetry

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Nobuchika Okada ◽  
Digesh Raut ◽  
Qaisar Shafi
Keyword(s):  
Dark Matter ◽  
Gauge Symmetry ◽  
Domain Wall ◽  
Standard Model ◽  
Particle Physics ◽  
Inflection Point ◽  
Baryon Asymmetry ◽  
Grand Unification ◽  
The Standard Model ◽  
The Universe

AbstractTo address five fundamental shortcomings of the Standard Model (SM) of particle physics and cosmology, we propose a phenomenologically viable framework based on a $$U(1)_X \times U(1)_{PQ}$$ U ( 1 ) X × U ( 1 ) PQ extension of the SM, that we call “SMART U(1)$$_X$$ X ”. The $$U(1)_X$$ U ( 1 ) X gauge symmetry is a well-known generalization of the $$U(1)_{B-L}$$ U ( 1 ) B - L symmetry and $$U(1)_{PQ}$$ U ( 1 ) PQ is the global Peccei–Quinn (PQ) symmetry. Three right handed neutrinos are added to cancel $$U(1)_X$$ U ( 1 ) X related anomalies, and they play a crucial role in understanding the observed neutrino oscillations and explaining the observed baryon asymmetry in the universe via leptogenesis. Implementation of PQ symmetry helps resolve the strong CP problem and also provides axion as a compelling dark matter (DM) candidate. The $$U(1)_X$$ U ( 1 ) X gauge symmetry enables us to implement the inflection-point inflation scenario with $$H_{inf} \lesssim 2 \times 10^{7}$$ H inf ≲ 2 × 10 7  GeV, where $$H_{inf}$$ H inf is the value of Hubble parameter during inflation. This is crucial to overcome a potential axion domain wall problem as well as the axion isocurvature problem. The SMART U(1)$$_X$$ X framework can be successfully implemented in the presence of SU(5) grand unification, as we briefly show.

Chapter 1 Physics Goal of BES-III

2009 ◽  
Vol 24 (supp01) ◽  
pp. 3-7 ◽  
Author(s):  
Jian-Ping Ma
Keyword(s):  
Elementary Particle ◽  
Standard Model ◽  
Quantum Chromodynamics ◽  
Particle Physics ◽  
New Physics ◽  
The Other ◽  
Fundamental Theory ◽  
Elementary Particle Physics ◽  
The Standard Model

The Standard Model (SM) has been successful at describing all relevant experimental phenomena and, thus, has been generally accepted as the fundamental theory of elementary particle physics. Despite its success, the SM leaves many unanswered questions. These can be classified into two main categories: one for subjects related to possible new physics at unexplored energy scales and the other for nonperturbertive physics, mostly related to Quantum Chromodynamics…

scholarly journals Outstanding questions: physics beyond the Standard Model

2012 ◽  
Vol 370 (1961) ◽  
pp. 818-830 ◽  
Author(s):  
John Ellis
Keyword(s):  
Dark Matter ◽  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
The Difference ◽  
The Universe

The Standard Model of particle physics agrees very well with experiment, but many important questions remain unanswered, among them are the following. What is the origin of particle masses and are they due to a Higgs boson? How does one understand the number of species of matter particles and how do they mix? What is the origin of the difference between matter and antimatter, and is it related to the origin of the matter in the Universe? What is the nature of the astrophysical dark matter? How does one unify the fundamental interactions? How does one quantize gravity? In this article, I introduce these questions and discuss how they may be addressed by experiments at the Large Hadron Collider, with particular attention to the search for the Higgs boson and supersymmetry.

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