Physics of warped dimensions and continuous spectra

We study some features of a warped five-dimensional model that solves the hierarchy problem and exhibits a continuum of Kaluza-Klein (KK) modes with a mass gap at the TeV scale. We compute the propagators and spectral functions for massless bulk gauge bosons, and study how the continuum can be reached as the limit of a set of models with discrete spectrum. Finally, we study the low energy effective theory and provide explicit results for the Wilson coefficients.

Implications for the hierarchy problem, inflation and geodesic motion from fiber fabric of spacetime

In this paper, we represent a resolution for the hierarchy problem where the inverse size of the extra dimension and the fundamental Planck scale would all be of the order of the TeV scale by proposing a fiber fabric of spacetime. The origin of the large hierarchy is essentially due to the $$\cosh $$ cosh function which is physically originated from the dynamics of the horizontal metric in the vacuum of non-zero energy. In addition, the fiber fabric of spacetime allows us to resolve elegantly and naturally the problems of the chirality fermions and stabilizing potential for the size of the extra dimension, which are usually encountered in the higher dimensional theories. Then, we explore the inflation with the modulus of the extra dimension identified as the inflaton where our slow-roll inflationary model belongs to the E-model class with $$n=1$$ n = 1 . We calculate the main inflationary observables which are consistent with the present experiments. Finally, we study how the geodesic motion of neutral test particles gets modified from the extension of spacetime. We compute the radius of the photon sphere, the innermost stable circular orbit, the perihelion shift, the light bending angle, and the observables of the strong gravitational lensing and the retrolensing phenomenon. By comparing the predicted values with the experimental observations, we determine the constraints on the fiber fabric of spacetime.

New species of fermions and bosons, cosmological constant problem and a farewell to spin–statistics theorem

If dark matter exists in the form of ultralight fermionic and bosonic species, then (a) it can accelerate evaporation of astrophysical black holes to the extent that their lifetimes can be reduced to astronomical time scales, a and (b) if there are extremely large number of such species it has the potential to solve the hierarchy problem [H. Davoudiasl, P. B. Denton and D. A. McGady, Phys. Rev. D 103 (2021) 055014; G. Dvali, Fortschr. Phys. 58 (2010) 528]. Here, we put forward a proposal that darkness of many of these new particles is natural, and in addition, the net zero point energy of the fermions exactly cancels that coming from the new bosons. The needed fermion–boson equality, and matching the fermion–boson degrees of freedom, comes about naturally. A very direct argument that allows the departure from the spin–statistics theorem is presented.

Twin Higgs portal dark matter

Many minimal models of dark matter (DM) or canonical solutions to the hierarchy problem are either excluded or severely constrained by LHC and direct detection null results. In particular, Higgs Portal Dark Matter (HPDM) features a scalar coupling to the Higgs via a quartic interaction, and obtaining the measured relic density via thermal freeze-out gives definite direct detection predictions which are now almost entirely excluded. The Twin Higgs solves the little hierarchy problem without coloured top partners by introducing a twin sector related to the Standard Model (SM) by a discrete symmetry. We generalize HPDM to arbitrary Twin Higgs models and introduce Twin Higgs Portal Dark Matter (THPDM), which features a DM candidate with an SU(4)-invariant quartic coupling to the Twin Higgs scalar sector. Given the size of quadratic corrections to the DM mass, its most motivated scale is near the mass of the radial mode. In that case, DM annihilation proceeds with the full Twin Higgs portal coupling, while direct detection is suppressed by the pNGB nature of the 125 GeV Higgs. For a standard cosmological history, this results in a predicted direct detection signal for THPDM that is orders of magnitude below that of HPDM with very little dependence on the precise details of the twin sector, evading current bounds but predicting possible signals at next generation experiments. In many Twin Higgs models, twin radiation contributions to ∆Neff are suppressed by an asymmetric reheating mechanism. We study this by extending the νMTH and X MTH models to include THPDM and compute the viable parameter space according to the latest CMB bounds. The injected entropy dilutes the DM abundance as well, resulting in additional suppression of direct detection below the neutrino floor.

Analysis of Student Errors in Solving Mathematics Problems Based on Watson's Criteria on the Subject of Two Variable Linear Equation System (SPLDV)

The purpose of the study was to describe the types of student errors and the factors that caused students to make mistakes in solving a two-variable system of linear equations based on Watson's criteria for class VIII MTs Pattuku. This type of research is descriptive research using a qualitative approach. The subjects in this study were students of class VIII MTs Pattuku then chose 3 subjects to be interviewed who had the most types of errors based on Watson's criteria. The research instrument used was a diagnostic test consisting of 3 questions about a two-variable linear equation system and interview guidelines. From the results of this study, it shows that there are no students who make mistakes in missing data (committed data) and indirect manipulation (undirected manipulation). 16% made incorrect data errors (innapropriate data), 40% made incorrect procedural errors (innapropriate procedure), 68% made an omitted conclusion error, 24% made a response level conflict error, 36% made mistakes in the skill hierarchy problem, and 48% made mistakes other than the 7 categories above (above other).

Kesalahan Peserta Didik Menyelesaikan Soal Cerita Pada Materi Matriks Berdasarkan Kriteria Watson

This study aimed to describe the errors made by students in working on math story problems on the subject of the matrix based on Watson's error criteria. This type of research was descriptive research with quantitative methods. This study's data collection techniques used the method of tests, interviews, and documentation, while the subjects in this study were 35 people. The test was carried out only once with many questions of 4 story questions. Then the data obtained were analyzed by data triangulation techniques. This study indicated that most errors made by students were incorrect data errors (inappropriate data / ID) with an error percentage of 20.39%. In comparison, the minor errors made by students were omitted data (OD) errors with an error percentage of 2.63%. For the omitted conclusion (OC) error, response level conflict (RLC), indirect manipulation (UM), skill hierarchy problem (SHP), and in addition to the seven errors (others/ O) with an error percentage range of 10%≤ P<25% and for inappropriate procedure errors (IP) with an error percentage range of P <10%. The causes of errors were lack of accuracy in reading and solving problems, errors in performing calculations, errors in using formulas, and lack of understanding of the material.

Analisis Kesalahan Siswa SD Dalam Menyelesaikan Permasalahan Luas Gabungan Bangun Datar Berdasarkan Watson’s Error Category

Geometry is a branch of mathematics and is one of the subject matter in mathematics in elementary schools. Measurement of area is one of the fundamental topics in mathematics. In fact, with regard to broad measurement skills, most of the students have difficulty in describing the problem. the mistakes that students make in answering a problem or problem need to be identified, the information obtained about errors in answering math problems can be used in improving mathematics teaching and learning activities. The purpose of this study was to identify errors made in solving the broad problem of combining data shapes based on the Watson error category. This type of research is descriptive qualitative research. The subjects used were 6 4th grade students of MI Nurul Huda with three different ability criteria. The selection is based on the advice of the math teacher and the daily test scores of the previous material. The results of the study show that the errors made by the research are missing conclusion errors, incorrect data errors, incorrect procedures, missing data error, and skill hierarchy problem