Weyl semimetals are topological materials whose electron quasiparticles obey the Weyl equation.They possess many unusual properties that may lead to new applications.This is a tutorial review of the optical properties...Weyl semimetals are topological materials whose electron quasiparticles obey the Weyl equation.They possess many unusual properties that may lead to new applications.This is a tutorial review of the optical properties and applications of Weyl semimetals.We review the basic concepts and optical responses of Weyl semimetals,and survey their applications in optics and thermal photonics.We hope this pedagogical text will motivate further research on this emerging topic.展开更多
The author uses a low temperature and low entropy pre inflation state to create a bridge between String theory and loop quantum gravity. We use this analysis in lieu of the CMB barrier as of z = 1000 since it is our w...The author uses a low temperature and low entropy pre inflation state to create a bridge between String theory and loop quantum gravity. We use this analysis in lieu of the CMB barrier as of z = 1000 since it is our way to come up with a working model of quintessence scalar fields, which permits relic generation of dark matter and dark energy. Not only referencing this bridge, we do it in such a way as to utilize the low entropy condition which the Brane world model of Randal and Sundrum creates, and to show how it is in common with what Caroll and Chen wrote up in 2005., i.e. when the universe was about 1000 times smaller and 100,000 times younger than today.展开更多
Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still unknown.In this paper,we investigate the formation of SMBHs from the quantum chromodynamics(Q...Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still unknown.In this paper,we investigate the formation of SMBHs from the quantum chromodynamics(QCD)axion bubbles.In this case,primordial black holes(PBHs)are considered as the seeds of SMBHs,which are generated from the QCD axion bubbles due to an explicit Peccei–Quinn(PQ)symmetry breaking after inflation.The QCD axion bubbles are formed when the QCD axion starts to oscillate during the QCD phase transition.We consider a general case in which the axion bubbles are formed with the bubble effective angle θ_(eff)∈(0,π],leading to the minimum PBH mass∼■(10^(4)−10^(7))M⊙for the axion decay constant f_(a)∼■(10^(16))GeV.The PBHs at this mass region may account for the seeds of SMBHs.展开更多
The axion or axion-like particle motivated from a natural solution of strong CP problem or string theory is a promising dark matter candidate.We study the new observational effects of ultralight axion-like particles b...The axion or axion-like particle motivated from a natural solution of strong CP problem or string theory is a promising dark matter candidate.We study the new observational effects of ultralight axion-like particles by the space-borne gravitational wave detector and the radio telescope.Taking the neutron star-black hole binary as an example,we demonstrate that the gravitational waveform could be obviously modified by the slow depletion of the axion cloud around the black hole formed through the superradiance process.We compare these new effects on the binary with the well-studied effects from dynamical friction with dark matter and dipole radiation in model-independent ways.Finally,we discuss the constraints from LIGO/Virgo and study the detectability of the ultralight axion particles at LISA and TianQin.展开更多
The haloscope based on the TM_(010)mode cavity is a well-established technique for detecting QCD axions.However,the method has limitations in detecting high-mass axion due to significant volume loss in the high-freque...The haloscope based on the TM_(010)mode cavity is a well-established technique for detecting QCD axions.However,the method has limitations in detecting high-mass axion due to significant volume loss in the high-frequency cavity.Utilizing a higher-order mode cavity can effectively reduce the volume loss of the high-frequency cavity.The rotatable dielectric pieces as a tuning mechanism can compensate for the degradation of the form factor of the higher-order mode.Nevertheless,the introduction of dielectric causes additional volume loss.To address these issues,this paper proposes a novel design scheme by adding a central metal rod to the higher-order mode cavity tuned by dielectrics,which improves the performance of the haloscope due to the increased effective volume of the cavity detector.The superiority of the novel design is demonstrated by comparing its simulated performance with previous designs.Moreover,the feasibility of the scheme is verified by the full-wave simulation results of the mechanical design model.展开更多
In 2003, Guth posed the following question in a KITP seminar in UCSB. Namely “Even if there exist 101000 vacuum states produced by String theory, does inflation produce overwhelmingly one preferred type of vacuum sta...In 2003, Guth posed the following question in a KITP seminar in UCSB. Namely “Even if there exist 101000 vacuum states produced by String theory, does inflation produce overwhelmingly one preferred type of vacuum states over the other possible types of vacuum states”? This document tries to answer how a preferred vacuum state could be produced, and by what sort of process. We construct a di quark condensate leading to a cosmological constant in line with known physical observations. We use a phase transition bridge from a tilted washboard potential to the chaotic inflationary model pioneered by Guth which is congruent with the slow roll criteria. This permits criteria for initiation of graviton production from a domain wall formed after a transition to a chaotic inflationary potential. It also permits investigation of if or not axion wall contributions to inflation are necessary. If we reject an explicit axion mass drop off to infinitesimal values at high temperatures, we may use the Bogomolnyi inequality to rescale and reset initial conditions for the chaotic inflationary potential. Then the Randall-Sundrum brane world effective potential delineates the end of the dominant role of di quarks, and the beginning of inflation. And perhaps answers Freeman Dysons contention that Graviton production is unlikely given present astrophysical constraints upon detector systems. We end this with a description in the last appendix entry, Appendix VI, as to why, given the emphasis upon di quarks, as to the usefulness of using times before Planck time interval as to modeling our physical system and its importance as to emergent field structures used for cosmological modeling.展开更多
We suggest that the unusual events observed by the ANITA experiment originate from axion particles traversing the Earth. Under the influence of the geomagnetic field, the axion may oscillate into a photon and vice-ver...We suggest that the unusual events observed by the ANITA experiment originate from axion particles traversing the Earth. Under the influence of the geomagnetic field, the axion may oscillate into a photon and vice-versa. To amplify the axion transition into photon, we consider that the phenomenon takes place at resonance, where the effective photon mass is equal to the axion mass. This requirement fixes the axion mass at 44 eV. An axion at this mass scale reproduces the cold dark matter scenario. If our interpretation prevails, with the help of axions we can establish an axion tomography of the Earth.展开更多
The results of a series of experiments on 3-photon annihilation of positrons and electrons, including the energy-angular correlation, angular distribution, energy spectrum and linear polarization of the annihilation p...The results of a series of experiments on 3-photon annihilation of positrons and electrons, including the energy-angular correlation, angular distribution, energy spectrum and linear polarization of the annihilation photons, the method of measuring the intensities of 3-photon annihilation, and the upper limit of axion production in the triplet positronium decay, are reported.展开更多
Building on the various manifestations of the forces latent in the quantum vacuum of spacetime such as Hawking’s radiation and Unruh temperature, we resolve a major paradox connected to an immensely important proposa...Building on the various manifestations of the forces latent in the quantum vacuum of spacetime such as Hawking’s radiation and Unruh temperature, we resolve a major paradox connected to an immensely important proposal by NASA scientists for constructing a practically fuelless spacecraft. In a nutshell, preliminary laboratory work shows that NASA’s electromagnetic drive project is viable and several experiments and measurements show it is real. Yet the proposal violates a fundamental principle of classical mechanics, namely Newton’s third law. The resolution of this paradox is quite straight forward in principle. It is simply the case that although the proposal seems to be based on classical mechanics and classical thinking it is only superficially so. Deep at the roots, the EM drive proposal of NASA is not classical physics but rather based on the vacuum forces of quantum cosmology and the theory of dark energy density of the universe. In fact the proposal is deeply linked to Hawking’s radiation and Unruh temperature, which is explained in some detail in the main body of the present short paper within the frame work of E-infinity Cantorian spacetime theory and D. Gross’ Heterotic superstring theory. In short the quintessence of our explanation is to regard the EM drive as a quasi electromagnetic cavity with an effective event horizon akin to that of a Hawking black hole emitting radiation causing ultimately the needed thrust to push the spacecraft forwards. In addition and by invoking fractal spacetime self similarity we show that a spacecraft will be subject to another cosmic thrust on the large scale of the entire cosmos.展开更多
We examine from first principles the implications of the 5th Randall Sundrum Brane world dimension in terms of setting initial conditions for chaotic inflationary physics. Our model pre-supposes that the inflationary ...We examine from first principles the implications of the 5th Randall Sundrum Brane world dimension in terms of setting initial conditions for chaotic inflationary physics. Our model pre-supposes that the inflationary potential pioneered by Guth is equivalent in magnitude in its initial inflationary state to the effective potential presented in the Randall-Sundrum model. We also consider an axion contribution to chaotic inflation (which may have a temperature dependence) which partly fades out up to the point of chaotic inflation being matched to a Randall-Sundrum effective potential. If we reject an explicit axion mass drop off to infinitesimal values at high temperatures, we may use the Bogomolnyi inequality to re-scale and reset initial conditions for the chaotic inflationary potential. One of the potential systems embedded in the Randall-Sundrum brane world is a model with a phase transition bridge from a tilted washboard potential to the chaotic inflationary model pioneered by Guth which is congruent with the slow roll criteria. If, as written up earlier, the axion wall contribution is due to di-quarks, which is equivalent to tying in baryogenesis to the formation of chaotic inflation initial conditions, with the Ran-dall-Sundrum brane world effective potential delineating the end of the dominant role of di-quarks, and the beginning of inflation.展开更多
Recently torsion fields were introduced in CP-violating cosmic axion a2-dynamos [Garcia de Andrade, Mod Phys Lett A, (2011)] in order to obtain Lorentz violating bounds for torsion. Here instead, oscillating axion sol...Recently torsion fields were introduced in CP-violating cosmic axion a2-dynamos [Garcia de Andrade, Mod Phys Lett A, (2011)] in order to obtain Lorentz violating bounds for torsion. Here instead, oscillating axion solutions of the dynamo equation with torsion modes [Garcia de Andrade, Phys Lett B (2012)] are obtained taking into account dissipative torsion fields. Magnetic helicity torsion oscillatory contribution is also obtained. Note that the torsion presence guarantees dynamo efficiency when axion dynamo length is much stronger than the torsion length. Primordial axion oscillations due to torsion yield a magnetic field of 109 G at Nucleosynthesis epoch. This is obtained due to a decay of BBN magnetic field of 1015 G induced by torsion. Since torsion is taken as 10–20 s–1, the dynamo efficiency is granted over torsion damping. Of course dynamo efficiency is better in the absence of torsion. In the particular case when the torsion is obtained from anomalies it is given by the gradient of axion scalar [Duncan et al., Nuclear Phys B 87, 215] that a simpler dynamo equation is obtained and dynamo mechanism seems to be efficient when the torsion helicity, is negative while magnetic field decays when the torsion is positive. In this case an extremely huge value for the magnetic field of 1015 Gauss is obtained. This is one order of magnitude greater than the primordial magnetic fields of the domain wall. Actually if one uses tDW ~ 10-4 s one obtains BDW ~ 1022 G which is a more stringent limit to the DW magnetic primordial field.展开更多
We analyze a model of cold axion dark matter weakly coupled with a dark gluon condensate, reproducing dark energy. We first review how to recover the dark energy behavior using the functional renormalization group app...We analyze a model of cold axion dark matter weakly coupled with a dark gluon condensate, reproducing dark energy. We first review how to recover the dark energy behavior using the functional renormalization group approach, and ground our study in the properties of the effective Lagrangian, to be determined non-perturbatively. Then, within the context of GSM×SU（2）D×U（1）PQ, we consider Yang-Mills condensate （YMC） interactions with QCD axions. We predict a transfer of dark energy density into dark matter density, that can be tested in the next generation of experiments dedicated to dark energy measurements. We obtain new bounds on the interactions between the Yang-Mills condensate and axion dark matter from Planck data：the new physics interaction scale related to the axion/gluon condensate mixing is constrained to be higher than the 106 GeV energy scale.展开更多
We review our most recent research on quantum transport,organizing the review according to the intensity of the magnetic field and focus mostly on topological semimetals and topological insulators.We first describe th...We review our most recent research on quantum transport,organizing the review according to the intensity of the magnetic field and focus mostly on topological semimetals and topological insulators.We first describe the phenomenon of quantum transport when a magnetic field is not present.We introduce the nonlinear Hall effect and its theoretical descriptions.Then,we discuss Coulomb instabilities in 3D higher-order topological insulators.Next,we pay close attention to the surface states and find a function to identify the axion insulator in the antiferromagnetic topological insulator MnBi2Te4.Under weak magnetic fields,we focus on the decaying Majorana oscillations which has the correlation with spin−orbit coupling.In the section on strong magnetic fields,we study the helical edge states and the one-sided hinge states of the Fermi-arc mechanism,which are relevant to the quantum Hall effect.Under extremely large magnetic fields,we derive a theoretical explanation of the negative magnetoresistance without a chiral anomaly.Then,we show how magnetic responses can be used to detect relativistic quasiparticles.Additionally,we introduce the 3D quantum Hall effect’s charge-density wave mechanism and compare it with the theory of 3D transitions between metal and insulator driven by magnetic fields.展开更多
One of the simplest ways to account for the observed W-boson mass shift is to introduce the SU(2)L triplet Higgs boson with zero hypercharge,whose vacuum expectation value is about 3 GeV.If the triplet is heavy enough...One of the simplest ways to account for the observed W-boson mass shift is to introduce the SU(2)L triplet Higgs boson with zero hypercharge,whose vacuum expectation value is about 3 GeV.If the triplet is heavy enough at O(1) TeV,it essentially contributes only to T parameter without any conflict with the observation.The presence of a complex triplet Higgs boson raises the SU(2)_(L) gauge coupling constant toα_(2)(M_(PL))≃1/44 at the Planck scale.Thanks to this larger gauge coupling constant,we show that the electroweak axion vacuum energy explains the observed cosmological constant provided that the axion field is located near the hill top of the potential at present.展开更多
This is a complete and exhaustive review on the so-called holographic axion model—a bottom-up holographic system characterized by the presence of a set of shift symmetric scalar bulk fields whose profiles are taken t...This is a complete and exhaustive review on the so-called holographic axion model—a bottom-up holographic system characterized by the presence of a set of shift symmetric scalar bulk fields whose profiles are taken to be linear in the spatial coordinates.This simple model implements the breaking of translational invariance of the dual field theory by retaining the homogeneity of the background geometry and therefore allowing for controllable and fast computations. The usages of this model are very vast and they are a proof of the spectacular versatility of the framework. In this review, we touch upon all the up-to-date aspects of this model from its connection with massive gravity and effective field theories, to its role in modeling momentum dissipation and elastic properties ending with all the phenomenological features and its hydrodynamic description. In summary, this is a complete guide to one of the most used models in Applied Holography and a must-read for any researcher entering this field.展开更多
基金supported by MURI projects from the U.S.Army Research Office(Grant No.W911NF-19-1-0279)the U.S.Air Force Office of Scientific Research(FA9550-21-1-0244).
文摘Weyl semimetals are topological materials whose electron quasiparticles obey the Weyl equation.They possess many unusual properties that may lead to new applications.This is a tutorial review of the optical properties and applications of Weyl semimetals.We review the basic concepts and optical responses of Weyl semimetals,and survey their applications in optics and thermal photonics.We hope this pedagogical text will motivate further research on this emerging topic.
文摘The author uses a low temperature and low entropy pre inflation state to create a bridge between String theory and loop quantum gravity. We use this analysis in lieu of the CMB barrier as of z = 1000 since it is our way to come up with a working model of quintessence scalar fields, which permits relic generation of dark matter and dark energy. Not only referencing this bridge, we do it in such a way as to utilize the low entropy condition which the Brane world model of Randal and Sundrum creates, and to show how it is in common with what Caroll and Chen wrote up in 2005., i.e. when the universe was about 1000 times smaller and 100,000 times younger than today.
基金supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 11775025 and No. 12175027)supported by the National Key R&D Program of China (Grant No. 2017YFA0402204)+1 种基金the CAS Project for Young Scientists in Basic Research YSBR-006the National Natural Science Foundation of China (NSFC) (Grant Nos. 11821505, No. 11825506, and No. 12047503)
文摘Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still unknown.In this paper,we investigate the formation of SMBHs from the quantum chromodynamics(QCD)axion bubbles.In this case,primordial black holes(PBHs)are considered as the seeds of SMBHs,which are generated from the QCD axion bubbles due to an explicit Peccei–Quinn(PQ)symmetry breaking after inflation.The QCD axion bubbles are formed when the QCD axion starts to oscillate during the QCD phase transition.We consider a general case in which the axion bubbles are formed with the bubble effective angle θ_(eff)∈(0,π],leading to the minimum PBH mass∼■(10^(4)−10^(7))M⊙for the axion decay constant f_(a)∼■(10^(16))GeV.The PBHs at this mass region may account for the seeds of SMBHs.
基金supported by the National Natural Science Foundation of China(Grant No.12205387)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2019B030302001)。
文摘The axion or axion-like particle motivated from a natural solution of strong CP problem or string theory is a promising dark matter candidate.We study the new observational effects of ultralight axion-like particles by the space-borne gravitational wave detector and the radio telescope.Taking the neutron star-black hole binary as an example,we demonstrate that the gravitational waveform could be obviously modified by the slow depletion of the axion cloud around the black hole formed through the superradiance process.We compare these new effects on the binary with the well-studied effects from dynamical friction with dark matter and dipole radiation in model-independent ways.Finally,we discuss the constraints from LIGO/Virgo and study the detectability of the ultralight axion particles at LISA and TianQin.
基金Project supported in part by the Equipment Development Project for Scientific Research of the Chinese Academy of Sciences(Grant No.YJKYYQ20190049)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301800)the National Key R&D Program of China(Grant No.2022YFA1603904)。
文摘The haloscope based on the TM_(010)mode cavity is a well-established technique for detecting QCD axions.However,the method has limitations in detecting high-mass axion due to significant volume loss in the high-frequency cavity.Utilizing a higher-order mode cavity can effectively reduce the volume loss of the high-frequency cavity.The rotatable dielectric pieces as a tuning mechanism can compensate for the degradation of the form factor of the higher-order mode.Nevertheless,the introduction of dielectric causes additional volume loss.To address these issues,this paper proposes a novel design scheme by adding a central metal rod to the higher-order mode cavity tuned by dielectrics,which improves the performance of the haloscope due to the increased effective volume of the cavity detector.The superiority of the novel design is demonstrated by comparing its simulated performance with previous designs.Moreover,the feasibility of the scheme is verified by the full-wave simulation results of the mechanical design model.
文摘In 2003, Guth posed the following question in a KITP seminar in UCSB. Namely “Even if there exist 101000 vacuum states produced by String theory, does inflation produce overwhelmingly one preferred type of vacuum states over the other possible types of vacuum states”? This document tries to answer how a preferred vacuum state could be produced, and by what sort of process. We construct a di quark condensate leading to a cosmological constant in line with known physical observations. We use a phase transition bridge from a tilted washboard potential to the chaotic inflationary model pioneered by Guth which is congruent with the slow roll criteria. This permits criteria for initiation of graviton production from a domain wall formed after a transition to a chaotic inflationary potential. It also permits investigation of if or not axion wall contributions to inflation are necessary. If we reject an explicit axion mass drop off to infinitesimal values at high temperatures, we may use the Bogomolnyi inequality to rescale and reset initial conditions for the chaotic inflationary potential. Then the Randall-Sundrum brane world effective potential delineates the end of the dominant role of di quarks, and the beginning of inflation. And perhaps answers Freeman Dysons contention that Graviton production is unlikely given present astrophysical constraints upon detector systems. We end this with a description in the last appendix entry, Appendix VI, as to why, given the emphasis upon di quarks, as to the usefulness of using times before Planck time interval as to modeling our physical system and its importance as to emergent field structures used for cosmological modeling.
文摘We suggest that the unusual events observed by the ANITA experiment originate from axion particles traversing the Earth. Under the influence of the geomagnetic field, the axion may oscillate into a photon and vice-versa. To amplify the axion transition into photon, we consider that the phenomenon takes place at resonance, where the effective photon mass is equal to the axion mass. This requirement fixes the axion mass at 44 eV. An axion at this mass scale reproduces the cold dark matter scenario. If our interpretation prevails, with the help of axions we can establish an axion tomography of the Earth.
文摘The results of a series of experiments on 3-photon annihilation of positrons and electrons, including the energy-angular correlation, angular distribution, energy spectrum and linear polarization of the annihilation photons, the method of measuring the intensities of 3-photon annihilation, and the upper limit of axion production in the triplet positronium decay, are reported.
文摘Building on the various manifestations of the forces latent in the quantum vacuum of spacetime such as Hawking’s radiation and Unruh temperature, we resolve a major paradox connected to an immensely important proposal by NASA scientists for constructing a practically fuelless spacecraft. In a nutshell, preliminary laboratory work shows that NASA’s electromagnetic drive project is viable and several experiments and measurements show it is real. Yet the proposal violates a fundamental principle of classical mechanics, namely Newton’s third law. The resolution of this paradox is quite straight forward in principle. It is simply the case that although the proposal seems to be based on classical mechanics and classical thinking it is only superficially so. Deep at the roots, the EM drive proposal of NASA is not classical physics but rather based on the vacuum forces of quantum cosmology and the theory of dark energy density of the universe. In fact the proposal is deeply linked to Hawking’s radiation and Unruh temperature, which is explained in some detail in the main body of the present short paper within the frame work of E-infinity Cantorian spacetime theory and D. Gross’ Heterotic superstring theory. In short the quintessence of our explanation is to regard the EM drive as a quasi electromagnetic cavity with an effective event horizon akin to that of a Hawking black hole emitting radiation causing ultimately the needed thrust to push the spacecraft forwards. In addition and by invoking fractal spacetime self similarity we show that a spacecraft will be subject to another cosmic thrust on the large scale of the entire cosmos.
文摘We examine from first principles the implications of the 5th Randall Sundrum Brane world dimension in terms of setting initial conditions for chaotic inflationary physics. Our model pre-supposes that the inflationary potential pioneered by Guth is equivalent in magnitude in its initial inflationary state to the effective potential presented in the Randall-Sundrum model. We also consider an axion contribution to chaotic inflation (which may have a temperature dependence) which partly fades out up to the point of chaotic inflation being matched to a Randall-Sundrum effective potential. If we reject an explicit axion mass drop off to infinitesimal values at high temperatures, we may use the Bogomolnyi inequality to re-scale and reset initial conditions for the chaotic inflationary potential. One of the potential systems embedded in the Randall-Sundrum brane world is a model with a phase transition bridge from a tilted washboard potential to the chaotic inflationary model pioneered by Guth which is congruent with the slow roll criteria. If, as written up earlier, the axion wall contribution is due to di-quarks, which is equivalent to tying in baryogenesis to the formation of chaotic inflation initial conditions, with the Ran-dall-Sundrum brane world effective potential delineating the end of the dominant role of di-quarks, and the beginning of inflation.
文摘Recently torsion fields were introduced in CP-violating cosmic axion a2-dynamos [Garcia de Andrade, Mod Phys Lett A, (2011)] in order to obtain Lorentz violating bounds for torsion. Here instead, oscillating axion solutions of the dynamo equation with torsion modes [Garcia de Andrade, Phys Lett B (2012)] are obtained taking into account dissipative torsion fields. Magnetic helicity torsion oscillatory contribution is also obtained. Note that the torsion presence guarantees dynamo efficiency when axion dynamo length is much stronger than the torsion length. Primordial axion oscillations due to torsion yield a magnetic field of 109 G at Nucleosynthesis epoch. This is obtained due to a decay of BBN magnetic field of 1015 G induced by torsion. Since torsion is taken as 10–20 s–1, the dynamo efficiency is granted over torsion damping. Of course dynamo efficiency is better in the absence of torsion. In the particular case when the torsion is obtained from anomalies it is given by the gradient of axion scalar [Duncan et al., Nuclear Phys B 87, 215] that a simpler dynamo equation is obtained and dynamo mechanism seems to be efficient when the torsion helicity, is negative while magnetic field decays when the torsion is positive. In this case an extremely huge value for the magnetic field of 1015 Gauss is obtained. This is one order of magnitude greater than the primordial magnetic fields of the domain wall. Actually if one uses tDW ~ 10-4 s one obtains BDW ~ 1022 G which is a more stringent limit to the DW magnetic primordial field.
基金Supported by the Shanghai Municipality(KBH1512299)Fudan University(JJH1512105)
文摘We analyze a model of cold axion dark matter weakly coupled with a dark gluon condensate, reproducing dark energy. We first review how to recover the dark energy behavior using the functional renormalization group approach, and ground our study in the properties of the effective Lagrangian, to be determined non-perturbatively. Then, within the context of GSM×SU（2）D×U（1）PQ, we consider Yang-Mills condensate （YMC） interactions with QCD axions. We predict a transfer of dark energy density into dark matter density, that can be tested in the next generation of experiments dedicated to dark energy measurements. We obtain new bounds on the interactions between the Yang-Mills condensate and axion dark matter from Planck data：the new physics interaction scale related to the axion/gluon condensate mixing is constrained to be higher than the 106 GeV energy scale.
基金This work was supported by the National Key R&D Program of China(No.2022YFA1403700)the National Natural Science Foundation of China(No.11925402)+1 种基金Guangdong province(Nos.2020KCXTD001 and 2016ZT06D348)the Science,Technology and Innovation Commission of Shenzhen Municipality(Nos.ZDSYS20170303165926217,JAY20170412152620376,and KYTDPT20181011104202253).
文摘We review our most recent research on quantum transport,organizing the review according to the intensity of the magnetic field and focus mostly on topological semimetals and topological insulators.We first describe the phenomenon of quantum transport when a magnetic field is not present.We introduce the nonlinear Hall effect and its theoretical descriptions.Then,we discuss Coulomb instabilities in 3D higher-order topological insulators.Next,we pay close attention to the surface states and find a function to identify the axion insulator in the antiferromagnetic topological insulator MnBi2Te4.Under weak magnetic fields,we focus on the decaying Majorana oscillations which has the correlation with spin−orbit coupling.In the section on strong magnetic fields,we study the helical edge states and the one-sided hinge states of the Fermi-arc mechanism,which are relevant to the quantum Hall effect.Under extremely large magnetic fields,we derive a theoretical explanation of the negative magnetoresistance without a chiral anomaly.Then,we show how magnetic responses can be used to detect relativistic quasiparticles.Additionally,we introduce the 3D quantum Hall effect’s charge-density wave mechanism and compare it with the theory of 3D transitions between metal and insulator driven by magnetic fields.
基金supported in part by the China Grant for Talent Scientific Start-Up Projectby the Natural Science Foundation of China(NSFC)under Grant No.12175134+1 种基金by World Premier International Research Center Initiative(WPI Initiative),MEXT,Japansupported by a start-up grant from Zhejiang University。
文摘One of the simplest ways to account for the observed W-boson mass shift is to introduce the SU(2)L triplet Higgs boson with zero hypercharge,whose vacuum expectation value is about 3 GeV.If the triplet is heavy enough at O(1) TeV,it essentially contributes only to T parameter without any conflict with the observation.The presence of a complex triplet Higgs boson raises the SU(2)_(L) gauge coupling constant toα_(2)(M_(PL))≃1/44 at the Planck scale.Thanks to this larger gauge coupling constant,we show that the electroweak axion vacuum energy explains the observed cosmological constant provided that the axion field is located near the hill top of the potential at present.
基金the support of the Shanghai Municipal Science and Technology Major Project (Grant No. 2019SHZDZX01)the Spanish MINECO “Centro de Excelencia Severo Ochoa” Program (Grant No. SEV-2012-0249)+5 种基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, Information and Communication Technology (ICT) & Future Planning (Grant No. NRF2017R1A2B4004810)the Gwangju Institute of Science and Technology (GIST) Research Institute (GRI) grant funded by the GIST in 2020supported in part by the National Natural Science Foundation of China (Grant Nos. 12075298, 11991052, and 12047503)supported in part by the National Natural Science Foundation of China (Grant No. 11905024)Dalian University of Technology (Grant No. DUT19LK20)。
文摘This is a complete and exhaustive review on the so-called holographic axion model—a bottom-up holographic system characterized by the presence of a set of shift symmetric scalar bulk fields whose profiles are taken to be linear in the spatial coordinates.This simple model implements the breaking of translational invariance of the dual field theory by retaining the homogeneity of the background geometry and therefore allowing for controllable and fast computations. The usages of this model are very vast and they are a proof of the spectacular versatility of the framework. In this review, we touch upon all the up-to-date aspects of this model from its connection with massive gravity and effective field theories, to its role in modeling momentum dissipation and elastic properties ending with all the phenomenological features and its hydrodynamic description. In summary, this is a complete guide to one of the most used models in Applied Holography and a must-read for any researcher entering this field.
