We propose a model of inflation driven by minimal extension of SUSY, commonly known as MSSM. Starting from gauge invariant flat directions in the n = 4 level comprising of QQQL,QuQd,QuLe and uude, we construct the inflaton potential and employ it to investigate for its consequences around the saddle point arising from the non-vanishing fourth derivative of the original potential. To this end, we derive the expressions for the important parameters in MSSM inflation using the loop corrected potential. We further estimate the observable parameters and find them to fit well with recent observational data from WMAP7 by using the code CAMB. We also explore the possibility of primordial black hole formation from our model. Finally, we analyze one loop RGE and compute different phenomenological parameters which could be precisely determined in LHC or future Linear Colliders.
We study the fine-tuning problem on the initial condition of inflation in the minimal supersymmetric standard model (MSSM), associated with the narrowness of the slow-roll region. We consider two cases before the onset of the MSSM inflation, namely, the radiation dominated era and preceding inflationary era. We find thermal dissipation does not induce additional friction to the inflaton, so that it does not help enlarge the slow-roll region. We argue thermal correction to the potential in the preceding radiation dominated era and quantum fluctuations in the preceding inflationary era disturb f…
We study an extension of the MSSM with a fourth generation of chiral matter. With this extension no value of $\tb$ allows the theory to stay perturbative up to the GUT scale. We suggest one model with extra vector-like states at the TeV scale that allows perturbativity all the way up to the GUT scale.
A new scenario of hybrid-like inflation is considered for sneutrino and MSSM fields. Contrary to the usual hybrid inflation model, the direct coupling between a trigger field and the sneutrino/MSSM inflaton field is not necessary for the scenario. The dissipation and the radiation from the sneutrino/MSSM inflaton can be written explicitly by using the Yukawa couplings. Remote inflation does not require the shift symmetry or cancellation in solving the eta-problem.
Inflation can occur near a point of inflection in the potential of flat directions of the Minimal Supersymmetric Standard Model. In this paper we elaborate on the complementarity between the bounds from Cosmic Microwave Background measurements, dark matter and particle physics phenomenology in determining the underlying parameters of MSSM inflation by specializing to the Minimal Supergravity scenario. We show that the future measurements from the Large Hadron Collider in tandem with all these constraints will significantly restrict the allowed parameter space. We also suggest a new perspective…
We consider a class of models in which minimal gauged F-term hybrid inflation is coupled renormalisably to the minimal supersymmetric standard model (MSSM), with no extra ingredients; we call this class the "minimal hybrid inflationary supersymmetric standard model" (MHISSM). The singlet inflaton supplies the Higgs mu-term, and allows an exit from inflation to a vacuum characterised by large Higgs vevs. The true ground state is reached after an period of thermal inflation along the Higgs flat direction. The scalar spectral index is reduced from the standard F-term value, to approximately 0.976…
We explored a Higgs inflationary scenario in the SUGRA embedding of the MSSM in Einstein frame where the inflaton is contained in the $SU(2)$ Higgs doublet. We include all higher order non-renormalizable terms to the MSSM superpotential and an appropriate Kähler potential which can provide slow-roll inflaton potential in the $D-$flat direction. In this model, a plateau-like inflation potential can be obtained if the imaginary part of the neutral Higgs acts as the inflaton. The inflationary predictions of this model are consistent with the latest CMB observations. The model represents a success…
Within the MSSM we propose the chaotic inflationary scenario in which the inflaton field is a combination of sleptons and the Higgs field states evolving along the $D$-term flat direction. In the inflation and postinflation reheating processes, a decisive role is played by the MSSM Yukawa superpotential. The vacuum energy during the inflationary era is mainly from the muonic Yukawa coupling, while the inflaton decay and subsequent reheating process dominantly proceeds due to the strange quark Yukawa term. Because of these, the presented scenario is predictive and the results obtained agree wel…
Adopting a recently proposed single-superfield framework of supergravity inflation, we consider large field inflationary models in which MSSM Higgs-like fields play the role of the inflaton. In the simplest cases, the inflaton potential has a fractional power, which is different from that of the original Higgs inflation, and it can be tested by cosmological observations in near future. We find difficulties in identifying the inflaton with the MSSM Higgses and discuss possible candidates of the inflaton.
In this paper we will analyze generic predictions of an inflection-point model of inflation with Hubble-induced corrections and study them in light of the Planck data. Typically inflection-point models of inflation can be embedded within Minimal Supersymmetric Standard Model (MSSM) where inflation can occur below the Planck scale. The flexibility of the potential allows us to match the observed amplitude of the TT-power spectrum of the cosmic microwave background radiation with low and high multipoles, spectral tilt, and virtually mild running of the spectral tilt, which can put a bound on an …
We present the calculation of the light neutral CP-even Higgs mass in the MSSM for a heavy SUSY spectrum by resumming enhanced terms through fourth logarithmic order (N$^3$LL), keeping terms of leading order in the top Yukawa coupling $α_t$, and NNLO in the strong coupling $α_s$. To this goal, the three-loop matching coefficient for the quartic Higgs coupling of the SM to the MSSM is derived to order $α_t^2α_s^2$ by comparing the perturbative EFT to the fixed-order expression for the Higgs mass. The new matching coefficient is made available through an updated version of the program Himalaya. …
We consider the possibility that the vacuum energy density of the MSSM (Minimal Supersymmetric Standard Model) flat direction condensate involving the Higgses H_1 and H_2 is responsible for inflation. We also discuss how the finely tuned Higgs potential at high vacuum expectation values can realize {\it cosmologically} flat direction along which it can generate the observed density perturbations, and after the end of inflation -- the coherent oscillations of the Higgses reheat the universe with all the observed degrees of freedom, without causing any problem for the electroweak phase transitio…
Inflationary scenarios motivated by the Minimal Supersymmetric Standard Model (MSSM) where five scalar fields are non-minimally coupled to gravity are considered. The potential of the model and the function of non-minimal coupling are polynomials of two Higgs doublet convolutions. We show that the use of the strong coupling approximation allows to obtain inflationary parameters in the case when a combination of the four scalar fields plays a role of inflaton. Numerical calculations show that the cosmological evolution leads to inflationary scenarios fully compatible with observational data for…
The inflation within the MSSM is proposed, where the inflaton field is a combination of the Higgs, squark and slepton states. While the inflationary phase is fully governed by the electron Yukawa superpotential coupling, the fields' condensates float along the flat $D$-term trajectory. This predicts the MSSM parameter $\tan β\simeq 13.1$ determined via the value of the curvature perturbation amplitude. The values of the scalar spectral index and the tensor-to-scalar ratio are predicted to be $n_s\simeq 0.966$ and $r=0.00118$. The postinflation reheating of the Universe proceeds by the radiativ…
A novel realization of the Starobinsky inflationary model within a moderate extension of the Minimal Supersymmetric Standard Model (MSSM) is presented. The proposed superpotential is uniquely determined by applying a continuous R and a Z_2 discrete symmetry, whereas the Kahler potential respects a no-scale-type SU(54,1)/SU(54)x U(1)_R x Z_2 symmetry too. The inflaton is identified with a Higgs-like modulus whose the vacuum expectation value controls the gravitational strength. Thanks to a strong enough coupling (with a parameter cT involved) between the inflaton and the Ricci scalar curvature,…
Inflation with plateau potentials give the best fit to the CMB observables as they predict tensor to scalar ratio stringently bounded by the observations from Planck and BICEP2/Keck. In supergravity models it is possible to obtain plateau potentials for scalar fields in the Einstein frame which can serve as the inflation potential by considering higher dimensional Planck suppressed operators and by the choice of non-canonical Kähler potentials. We construct a plateau inflation model in MSSM where the inflation occurs along a sneutrino-Higgs flat direction. A hidden sector Polonyi field is used…
We discuss the constraints on the inhomogeneous reheating scenario. In particular, we discuss the prospects for low scale inflation with a Hubble constant of the order of the gravitino mass, and the possibility that an MSSM flat direction is responsible for the density fluctuations. Thermal effects are generically fatal for the scenario, and can only be avoided for small enough mass and couplings of the flat direction field, excluding MSSM flat directions. Prompt decay at the end of inflation bypasses thermal constraints, and is compatible with both low scale inflation and MSSM flat directions…
Variants of the $A$-term model of hep-ph/0605035 are considered. They are equally successful, indicating that the model is quite robust once the relation between $A$ and the soft mass is regarded as tunable. Alternatively a flat direction might support modular inflation.
The cosmological evolution of the string landscape is expected to consist of multiple stages of old inflation with large cosmological constant ending by tunnelling. Old inflation has a well known graceful exit problem as the observable universe becomes empty, devoid of any entropy. Simultaneously, in the quest for reheating the right degrees of freedom, it is important that the final stage of inflation reheat Standard Model sector. It is known that inflation can occur naturally along a flat direction of the Minimal Supersymmetric Standard Model (MSSM), solving the reheating problem, but the in…
Non-perturbative preheating decay of post-inflationary condensates often results in a high density, low momenta, non-thermal gas. In the case where the non-perturbative classical evolution also leads to Q-balls, this effect shields them from instant dissociation, and may radically change the thermal history of the universe. For example, in a large class of inflationary scenarios, motivated by the MSSM and its embedding in string theory, the reheat temperature changes by a multiplicative factor of $10^{12}$.
Motivated by a recent discussion about the role of flat directions, a typical feature of supersymmetric models, in the process of particle production in the early universe a consistent model of inflation and preheating in supergravity with MSSM fields has been built. It is based on a model proposed by M. Kawasaki, M. Yamaguchi and T. Yanagida. In the inflationary stage, the flat directions acquire large vacuum expectation values (VEVs) without spoiling the background of slow-roll, high-scale inflation consistent with the latest WMAP5 observational data. In the stage of particle production, nat…
A {\it gauge invariant} combination of LLe {\it sleptons} within the Minimal Supersymmetric Standard Model is one of the few inflaton candidates that can naturally explain population of the observable sector and creation of matter after inflation. After the end of inflation, the inflaton oscillates coherently about the minimum of its potential, which is a point of {\it enhanced gauged symmetry}. This results in bursts of non-perturbative production of the gauge/gaugino and (s)lepton quanta. The subsequent decay of these quanta is very fast and leads to an extremely efficient transfer of the in…
We argue that all necessary ingredients for successful inflation are present in the flat directions of the minimal supersymmetric standard model (MSSM). Out of many gauge invariant combinations of the squarks, sleptons and Higgses, there are two flat directions, ${\bf LLe}$, and ${\bf udd}$, which are promising candidates for the inflaton. The model predicts more than $10^3$ e-foldings with an inflationary scale of $H_{\rm inf} \sim {\cal O}(1-10)$ GeV, provides a tilted spectrum $0.92 \leq n_s \leq 1$ with an amplitude of $δ_H \sim 10^{-5}$ and a negligible tensor perturbations. It yields a l…
We consider the supergravity origin of the recently proposed MSSM inflationary model, which relies on the existence of a saddle point along a dimension six flat direction. We derive the conditions that the Kahler potential has to satisfy for the saddle point to exist irrespective of the hidden sector vevs. We show that these conditions are satisfied by a simple class of Kahler potentials, which we find to have a similar form as in various string theory compactifications. For these potentials, slow roll MSSM inflation requires no fine tuning of the soft supersymmetry breaking parameters.
Supersymmetric theories, including the minimal supersymmetric standard model, usually contain many scalar fields whose potentials are absent in the exact supersymmetric limit and within the renormalizable level. Since their potentials are vulnerable to the finite energy density of the Universe through supergravity effects, these flat directions have nontrivial dynamics in the early Universe. Recently, we have pointed out that a flat direction may have a positive Hubble induced mass term during inflation whereas a negative one after inflation. In this case, the flat direction stays at the origi…
By assuming the existence of the sequential fourth generation to the minimal supersymmetric standard model (MSSM), we study the possibility of a strongly first-order electroweak phase transition. We find that there is a parameter region of the MSSM where the electroweak phase transition is strongly first order. In that parameter region, the mass of the lighter scalar Higgs boson is calculated to be above the experimental lower bound, and the scalar quarks of the third and the fourth generations are heavier than the corresponding quarks.
The parameter space for A-term inflation is explored with $W=λ_p ϕ^p/(p M_P^{p-3})$. With p=6 and λ_p~1, the observed spectrum and spectral tilt can be obtained with soft mass of order 10^2 GeV but not with a much higher mass. The case p=3 requires λ_p~10^{-9} to 10^{-12}. The ratio m/A requires fine-tuning, which may be justified on environmental grounds. An extension of the MSSM to include non-renormalizable terms and/or Dirac neutrino masses might support either A-term inflation or modular inflation.
Despite the fact that experimentally with a high degree of statistical significance only a single Standard Model--like Higgs boson is discovered at the LHC, extended Higgs sectors with multiple scalar fields not excluded by combined fits of the data are more preferable theoretically for internally consistent realistic models of particle physics. We analyze the inflationary scenarios which could be induced by the two-Higgs doublet potential of the Minimal Supersymmetric Standard Model (MSSM) where five scalar fields have nonminimal couplings to gravity. Observables following from such MSSM-insp…
The flat directions LLe and udd within the minimal supersymmetric Standard Model provide all the necessary ingredients for a successful inflation with the right amplitude of the scalar density perturbations, negligible gravity waves and the spectral tilt within 2σobserved range 0.92 \leq n_s \leq 1.0. In this paper we explore the available parameter space for inflation in conjunction with a thermal cold dark matter abundance within the minimal supergravity model. Remarkably for the inflaton, which is a combination of squarks and sleptons, there is a stau-neutralino coannihilation region below …
We consider instant preheating as the mechanism for generating the curvature perturbation at the end of chaotic inflation. Then we examine if inflation could be driven by a Minimal Supersymmetric Standard Model (MSSM) flat direction or a sneutrino. Our simple mechanism relaxes some serious constraints that appeared in past studies, making inflation driven by a MSSM flat direction or a sneutrino more plausible.
It has been recently pointed out that the polarization BICEP2 results are consistent with the identification of an inflaton mass m \simeq 10^{13} GeV with the SUSY breaking scale in an MSSM with a fine-tuned SM Higgs. This identification leads to a Higgs mass m_h \simeq 126 GeV, consistent with LHC measurements. Here we propose that this naturally suggests to identify the inflaton with the heavy MSSM Higgs system. The fact that the extrapolated Higgs coupling lambda_{SM}\simeq 0 at scales below the Planck scale suggests the Higgs degrees of freedom could be associated to a Wilson line or D-bra…
In the framework of MSSM inflation, matter and gravitino production are here investigated through the decay of the fields which are coupled to the udd inflaton, a gauge invariant combination of squarks. After the end of inflation, the flat direction oscillates about the minimum of its potential, losing at each oscillation about 56% of its energy into bursts of gauge/gaugino and scalar quanta when crossing the origin. These particles then acquire a large inflaton VEV-induced mass and decay perturbatively into the MSSM quanta and gravitinos, transferring the inflaton energy very efficiently via …
We investigate supersymmetric hybrid inflation in a realistic model based on the gauge symmetry $SU(4)_c \times SU(2)_L \times SU(2)_R$. The minimal supersymmetric standard model (MSSM) $μ$ term arises, following Dvali, Lazarides, and Shafi, from the coupling of the MSSM electroweak doublets to a gauge singlet superfield which plays an essential role in inflation. The primordial monopoles are inflated away by arranging that the $SU(4)_c \times SU(2)_L \times SU(2)_R$ symmetry is broken along the inflationary trajectory. The interplay between the (above) $μ$ coupling, the gravitino mass, and th…
We consider $μ$-term hybrid inflation which, in its minimal format with gravity mediated supersymmetry breaking, leads to split supersymmetry. The MSSM $μ$-term in this framework is larger than the gravitino mass $m_G$, and successful inflation requires $m_G$ (and hence also $|μ|$) $\gtrsim 5 \times 10^7$ GeV, such that the gravitino decays before the LSP neutralino freezes out. Assuming universal scalar masses of the same order as $m_G$, this leads to split supersymmetry. The LSP wino with mass $\simeq$ 2 TeV is a plausible dark matter candidate, the gluino may be accessible at the LHC, and t…
In light of recent experimental results, we present updated bounds on the lightest Higgs boson mass in the Standard Model (SM) and in the Minimal Supersymmetric extension of the Standard Model (MSSM). The vacuum stability lower bound on the SM Higgs boson mass lies above the MSSM lightest Higgs boson mass upper bound for a large amount of SUSY parameter space. We postulate a fourth generation of fermions to see how the area of inconsistency changes, and discover that the MSSM is salvagable if a fourth generation is added to the MSSM (MSSM4).
Modular cosmology is plagued by overproduction of unwanted relics, gravitinos and especially moduli, at relatively low energy scales. Thermal inflation provides a compelling solution to this moduli problem, but invalidates most baryogenesis scenarios. We propose a simple model in which the MSSM plus neutrino mass term $(LH_u)^2$ is supplemented by a minimal flaton sector to drive the thermal inflation, and make two crucial assumptions: the flaton vacuum expectation value generates the $μ$-term of the MSSM and $m_L^2 + m_{H_u}^2 < 0$. The second assumption is particularly interesting in that it…
We discuss constraints on which flat directions can have large vacuum expectation values (VEVs) after inflation. We show that only flat directions which are not charged under B-L and develop positive pressure due to renormalization group effects can have large VEVs of order $\Mp$. For example, within the MSSM only the $H_uH_d$ flat direction is found to be viable. This strongly constrains the embedding of a broad class of inflationary models in the MSSM or some other supersymmetric extension of the SM. For flat directions with negative pressure, the condensate fragments into very large Q-balls…
The Minimal Supersymmetry Standard Model contains several hundreds of D- and F-flat directions that are lifted by soft susy breaking terms as well as by non-renormalizable terms. In a recent paper we find that only two of these directions, {\bf LLe} and {\bf udd} can accommodate inflation. The model predicts more than $10^3$ e-foldings with an inflationary scale of $H_{\rm inf}\sim 1$ GeV, provides a tilted spectrum compatible with WMAP3, and a negligible tensor perturbation. The reheating temperature could be as low as $T_{rh}\sim 1$ TeV. The model is stable under radiative as well as supergr…
We consider low scale slow roll inflation driven by the gauge invariant flat directions {\bf udd} and {\bf LLe} of the Minimally Supersymmetric Standard Model at the vicinity of a saddle point of the scalar potential. We study the stability of saddle point and the slow roll regime by considering radiative and supergravity corrections. The latter are found to be harmless, but the former require a modest finetuning of the saddle point condition. We show that while the inflaton decays almost instantly, full thermalization occurs late, typically at a temperature $T\approx 10^{7}$ GeV, so that ther…
One interpretation of proton stability is the existence of extra-flat directions of the MSSM, in particular $u^{c}u^{c}d^{c}e^{c}$ and $QQQL$, where the operators lifting the potential are suppressed by a mass scale $Λ$ which is much larger than the Planck mass, $ Λ\gae 10^{26} \GeV$. Using D-term hybrid inflation as an example, we show that such flat directions can serve as the inflaton in SUSY inflation models. The resulting model is a minimal version of D-term inflation which requires the smallest number of additional fields. In the case where $Q$-balls form from the extra-flat direction co…
We study a $D$-term inflation scenario in a model extended from the minimal supersymmetric standard model (MSSM) by two additional abelian factor groups focussing on its particle physics aspects. Condensates of the fields related to the inflation can naturally give a possible solution to both the $μ$-problem in the MSSM and the neutrino mass through their nonrenormalizable couplings to the MSSM fields. Mixings between neutrinos and neutralinos are also induced by some of these condensates. Small neutrino masses are generated by a weak scale seesaw mechanism as a result of these mixings. Moreov…
Recent analyses have shown that a sequential fourth generation can be consistent with precision electroweak data. We consider the possibility that the new generation could be a mirror generation with $V+A$ rather than $V-A$ interactions. Specifically we consider an extension of the minimal supersymmetric standard model with a light mirror generation (mirMSSM) . Implications of this extension are explored. One consequence is an enhancement of the tau neutrino magnetic moment by several orders of magnitude consistent with the current limits on the magnetic moment of the tau. The masses of the mi…
A fourth generation of Standard Model (SM) fermions is usually considered unlikely due to constraints from direct searches, electroweak precision measurements, and perturbative unitarity. We show that fermion mass textures consistent with all constraints may be obtained naturally in a model with four generations constructed from intersecting D6 branes on a T^6/(Z_2 x Z_2) orientifold. The Yukawa matrices of the model are rank 2, so that only the third- and fourth-generation fermions obtain masses at the trilinear level. The first two generations obtain masses via higher-order couplings and are…
The generalization of the MSSM to the case of four chiral fermion generations (4GMSSM) can lead to significant changes in the phenomenology of the otherwise familiar Higgs sector. In most of the 3GMSSM parameter space, the lighter CP-even $h$ is $\sim 115-125$ GeV and mostly Standard Model-like while $H,A,H^\pm$ are all relatively heavy. Furthermore, the ratio of Higgs vevs, $\tan β$, is relatively unconstrained. In contrast to this, in the 4GMSSM, heavy fourth generation fermion loops drive the masses of $h,H,H^\pm$ to large values while the CP-odd boson, $A$, can remain relatively light and …
There is strong evidence from cosmological data that the universe underwent an epoch of superluminal expansion called inflation. A satisfactory embedding of inflation in fundamental physics has been an outstanding problem at the interface of cosmology and high energy physics. We show how inflation can be realized within the Minimal Supersymmetric Standard Model (MSSM). The inflaton candidates are two specific combinations of supersymmetric partners of quarks and leptons. MSSM inflation occurs at a low scale and generates perturbations in the range experimentally allowed by the latest data from…
We show that MSSM with three right handed neutrinos incorporating a renormalizable Type-I seesaw superpotential and no-scale SURGA Kähler potential can lead to a Starobinsky kind of inflation potential along a flat direction associated with gauge invariant combination of Higgs, slepton and right handed sneutrino superfields. The inflation conditions put constraints on the Dirac Yukawa coupling and the Majorana masses required for the neutrino masses and also demands the tuning among the parameters. The scale of inflation is set by the mass of the heaviest right handed neutrino. We also fit the…
Many models of high energy physics possess metastable vacua. It is conceivable that the universe can get trapped in such a false vacuum, irrespective of its origin and prior history, at an earlier stage during its evolution. The ensuing false vacuum inflation results in a cold and empty universe and has a generic graceful exit problem. We show that an inflection point inflation along the flat directions of the Minimal Supersymmetric Standard Model (MSSM) can resolve this graceful exit problem by inflating the bubble which nucleate out of a false vacuum. The important point is that the initial …
We consider the possibility that the dark energy responsible for inflation is deposited into extra dimensions outside of our observable universe. Reheating and all matter can then be obtained from the MSSM flat direction condensate involving the Higgses $H_u$ and $H_d$, which acquires large amplitude by virtue of quantum fluctuations during inflation. The reheat temperature is $T_{RH} \lesssim 10^9$ GeV so that there is no gravitino problem. We find a spectral index $n_s\approx 1$ with a very weak dependence on the Higgs potential.
We consider a phenomenological extension of the minimal supersymmetric standard model (MSSM) which incorporates non-minimal chaotic inflation, driven by a quadratic potential in conjunction with a linear term in the frame function. Inflation is followed by a Peccei-Quinn phase transition, based on renormalizable superpotential terms, which resolves the strong CP and mu problems of MSSM and provide masses lower than about 10^12 GeV for the right-handed (RH) (s)neutrinos. Baryogenesis occurs via non-thermal leptogenesis, realized by the out-of-equilibrium decay of the RH sneutrinos which are pro…
We consider observational constraints and fine-tuning issues in a renormalizable model of inflection point inflation, with two independent parameters. We derive constraints on the parameter space of this model arising from the WMAP 7-year power spectrum. It has previously been shown that it is possible to successfully embed this potential in the MSSM. Unfortunately, to do this requires severe fine-tuning. We address this issue by introducing a hybrid field to dynamically uplift the potential with a subsequent smooth phase transition to end inflation at the necessary point. Large parameter regi…
We study inflationary solutions in the M-theory. Including the fourth-order curvature correction terms, we find three generalized de Sitter solutions, in which our 3-space expands exponentially. Taking one of the solutions, we propose an inflationary scenario of the early universe. This provides us a natural explanation for large extra dimensions in a brane world, and suggests some connection between the 60 e-folding expansion of inflation and TeV gravity based on the large extra dimensions.
We explore the possibility of a fourth generation in the gauge-coupling-unified, minimal supersymmetric (MSSM) framework. We find that a sequential fourth generation (with a heavy neutrino $ν'$) can still fit, surviving all present experimental constraints, provided $λ_b(M_U)=λ_τ(M_U)$ Yukawa unification is relaxed. For the theory to remain perturbative up to $M_U$, the new leptonic generation must lie within reach of LEP-II and the new $b',t'$ must have masses within the reach of the Tevatron. For example, for $\mt>150\gev$ we find $m_{ν'},m_{τ'}< 86\gev$, $m_{t'}<178$, and $m_{b'}<156\gev$. …
Supersymmetric Unified theories which incorporate a renormalizable Type I seesaw mechanism for small neutrino masses can also provide slow roll inflection point inflation along a flat direction associated with a gauge invariant combination of the Higgs, slepton and right handed sneutrino superfields. Inflationary parameters are related to the Majorana and Dirac couplings responsible for neutrino masses with the scale of inflation set by a right-handed neutrino mass $M_{ν^c} \sim 10^6-10^{12}$ GeV. Tuning of the neutrino Dirac and Majorana superpotential couplings and soft Susy breaking paramet…
Following \cite{Lin:2009yt}, we explore the parameter space of the case when the supersymmetry (SUSY) breaking scale is lower, for example, in gauge mediated SUSY breaking model. During inflation, the form of the potential is $V_0$ plus MSSM (MSSM stands for Minimal Supersymmetric Standard Model) (or A term (It is called A-term inflation when the inflaton field is any direction (gauge or singlet) that generates an A-term.)) inflation. We show that the model works for a wide range of the potential $V_0$ with the soft SUSY breaking mass $m\sim O(1)$ TeV. The implication to MSSM (or A-term) infla…
We propose a novel reformulation of supersymmetric (more precisely $μ$-) hybrid inflation based on a local U(1) or any suitable extension of the minimal supersymmetric standard model (MSSM) which also resolves the $μ$ problem. We employ a suitable Kahler potential which effectively yields quartic inflation with non-minimal coupling to gravity. Imposing the gravitino Big Bang Nucleosynthesis (BBN) constraint on the reheat temperature ($T_r \lesssim 10^6$ GeV) and requiring a neutralino LSP, the tensor to scalar ratio ($r$) has a lower bound $r \gtrsim 0.004$. The U(1) symmetry breaking scale li…
We review the cosmological implications of the flat directions of the Minimally Supersymmetric Standard Model (MSSM). We describe how field condensates are created along the flat directions because of inflationary fluctuations. The post-inflationary dynamical evolution of the field condensate can charge up the condensate with B or L in a process known as Affleck-Dine baryogenesis. Condensate fluctuations can give rise to both adiabatic and isocurvature density perturbations and could be observable in future cosmic microwave experiments. In many cases the condensate is however not the state of …
