Softening the naturalness problem

It was observed by Veltman a long time ago that a special value for the Higgs boson mass could lead to a cancellation of the quadratically divergent corrections to the Higgs bosons squared mass which appear at one loop. We present a class of low energy models that allow one to soften the naturalness problem in the sense that there can be a cancellation of radiative corrections appearing at one loop. The naturalness problem is shifted from the 1 TeV region to the 10 TeV region. Depending on the specific model under consideration, this scale can even be shifted to a higher energy scale. Signatures of these models are discussed.Received: 11 September 2003, Published online: 12 November 2003     

Vacuum nucleon loops and naturalness

Phenomenological studies support the applicability of naturalness and naive dimensional analysis to hadronic effective lagrangians for nuclei. However, one-baryon-loop vacuum contributions in renormalizable models give rise to unnatural coefficients, which indicates that the quantum vacuum is not described adequately. The effective lagrangian framework accommodates a more general characterization of vacuum contributions without reference to a Dirac sea of nucleons.     

合成言语自然度的研究

在过去的十年中,中国科学院声学研究所建立了一个文语转换系统,它包括语音库,声调模型和基本合成规则．无限词汇的汉语合成问题初步解决,但合成言语的自然度必须进一步改进．我们对语言的音段特征和超音段特征对合成言语自然度的影响做了研究,结果表明影响合成言语自然度的基本因素是语言的节奏和协同发音．本系统所采用的声调模式适合于单句合成,对于大于单句的语言单元的合成,必须十分仔细地控制语调才能达成高自然度．本文介绍利用主观评价对合成语言自然度进行研究的方法和结果．     

On the concept of naturalness in string theories

We point out that string theory can provide an explanation for the vanishing of certain parameters in its low-energy limit which cannot be understood through the symmetries of the field-theoretic approximation. This fact may enable us to pinpoint stringy effects in the effective field theoretic limit.     

Renormalization group naturalness of GUT Higgs potentials

We analyze the symmetry-breaking patterns of grand unified theories from the point of view of a recently proposed criterion of renormalization-group naturalness. We perform the analysis on simple non-SUSY SU(5) and SO(10) and SUSY SU(5) GUTs. We find that the naturalness criterion can favor spontaneous symmetry breaking in the direction of the smallest of the maximal little groups. Some differences between theories with and without supersymmetry are also emphasized.     

On the naturalness of Einstein’s equation

We compute all 2-covariant tensors naturally constructed from a semi-Riemannian metric which are divergence-free and have weight greater than −2.     

Perceived naturalness of spectrally distorted speech and music

We determined how the perceived naturalness of music and speech (male and female talkers) signals was affected by various forms of linear filtering, some of which were intended to mimic the spectral "distortions" introduced by transducers such as microphones, loudspeakers, and earphones. The filters introduced spectral tilts and ripples of various types, variations in upper and lower cutoff frequency, and combinations of these. All of the differently filtered signals (168 conditions) were intermixed in random order within one block of trials. Levels were adjusted to give approximately equal loudness in all conditions. Listeners were required to judge the perceptual quality (naturalness) of the filtered signals on a scale from 1 to 10. For spectral ripples, perceived quality decreased with increasing ripple density up to 0.2 ripple/ERB(N) and with increasing ripple depth. Spectral tilts also degraded quality, and the effects were similar for positive and negative tilts. Ripples and/or tilts degraded quality more when they extended over a wide frequency range (87-6981 Hz) than when they extended over subranges. Low- and mid-frequency ranges were roughly equally important for music, but the mid-range was most important for speech. For music, the highest quality was obtained for the broadband signal (55-16,854 Hz). Increasing the lower cutoff frequency from 55 Hz resulted in a clear degradation of quality. There was also a distinct degradation as the upper cutoff frequency was decreased from 16,845 Hz. For speech, there was a marked degradation when the lower cutoff frequency was increased from 123 to 208 Hz and when the upper cutoff frequency was decreased from 10,869 Hz. Typical telephone bandwidth (313 to 3547 Hz) gave very poor quality.     

Experimental study on the naturalness of synthetic speech

In the past 10 years a Chinese text-to-speech system including aphonetic library,static tone model and basic synthesis rules had been estab-lished in IAAS.The Chinese synthesis of unrestricted vocabulary had beenachieved,but further steps must be taken to improve the naturalness ofsynthesized Chinese.The effect of segmental and suprasegmental features ofsynthetic speech upon naturalness have been studied by use of subjective as-sessment method.The results show that the rhythm in time domain andcoarticulation occupy a basic position for improving the naturalness of synthet-ic speech.And the fundamental frequency curve decided by tone model onlysuit to synthesize short sentence of Chinese.If the synthesis of larger linguisticunit than simple sentence is considered,the fundamental frequency curveshould be carefully manipulated.This paper presents the experimental methodand results,and discusses the way how to improve the naturalness of syntheticChinese.     

Model-independent Veltman condition,naturalness and the little hierarchy problem

We adopt a bottom-up Effective Field Theory(EFT)approach to derive a model-independent Veltman condition to cancel out the quadratic divergences in the Higgs mass.We show using the equivalence theorem that all the deviations in the Higgs couplings to the W and Z from the SM predictions should vanish.We argue based on tree-level unitarity that any new physics that naturally cancels out the quadratic divergences should be ≤19 TeV.We show that the level of fine-tuning required is unless the O(0:1%-1%) UV sector has a symmetry that forces the satisfaction of the model-independent Veltman condition,in which case all fine-tuning is eliminated.We also conjecture that,if no new physics that couples to the Higgs is observed up to~19 TeV,or if the Higgs couplings to the SM particles conform to the SM predictions,then the Higgs either does not couple to any UV sector or is fine-tuned.     

Higgs boson, renormalization group, and naturalness in cosmology

We consider the renormalization group improvement in the theory of the Standard Model (SM) Higgs boson playing the role of an inflaton with a strong non-minimal coupling to gravity. At the one-loop level with the running of constants taken into account, it leads to a range of the Higgs mass that is entirely determined by the lower WMAP bound on the cosmic microwave background (CMB) spectral index. We find that the SM phenomenology is sensitive to current cosmological data, which suggests to perform more precise CMB measurements as a SM test complementary to the LHC program. By using the concept of a field-dependent cutoff, we show the naturalness of the gradient and curvature expansion in this model within the conventional perturbation theory range of the SM. We also discuss the relation of these results to two-loop calculations and the limitations of the latter caused by parametrization and gauge dependence problems.     

A text-to-speech system with high intelligibility and naturalness for Chinese

I.IntroductionResearchesonChinesesynthesisdisclosethatonlywhenboththesegmentalandsupraseg-melltalfeaturesofthesyntheticspeecharesimilartothoseofthellaturalone,thesyntheticspeechwillsoundintelligibleandnatural[1].Amongekistingsynthetictechniques,theapproachbasedonacousticparametersca-nadustboththesegmentalandsuprasegmentalfeaturesofsyntheticunitsfiekiblyandcanbeconsideredasthemostreasonablesynthetictechniqueintheory.However,theparameterbasedsynthesizerisoverAfependentonthedevelopmentsofparamet…     

一种高清晰度、高自然度的汉语文语转换系统

以基音同步叠加技术为基础,以汉语单音节为合成单元,有一包含词调模式、重音模式和句调模式的韵律规则库的汉语文语转换系统,可合成出高清晰度和高自然度的汉语语音。研究表明,影响汉语合成语音的自然度的主要因素是音高和音强随时间的变化、各音节的音长分布以及音节间的协同发音,其中以音高和音长的影响最为显著。时域基音同步叠加技术提供了一种在时域改变语音波形的音高和音长的方法,从而使在用波形拼接法合成汉语时,进行词一级和句一级的韵律调节成为可能。对新闻广播语言的声学特征的分析,为建立汉语合成的韵律调节规则提供了理论依据。本文介绍新的汉语文语转换系统的结构及流程、对广播语言韵律特征的初步研究结果、汉语合成规则及合成系统语音质量的评测结果。