Майамигийн их сургуулийн судлаачид LIGO төхөөрөмжөөр бүртгэгдсэн ер бусын таталцлын долгионы дохио нь сансрын үүслийн эхэн үед бүрэлдсэн гэж үздэг “анхдагч хар нүх”-ний нотолгоо байж болзошгүйг мэдээлэв.
LIGO өнгөрсөн оны сүүлээр Нарнаас бага масстай объектуудын нэгдэл үүсгэсэн дохиог илрүүлжээ. Одон орон судлалын стандарт загварт ийм бага масстай хар нүх оршдоггүй тул энэ нь эрдэмтдийн анхаарлыг ихэд татаж байна. Их сургуулийн физикч Нико Каппеллути болон судлаач Альберто Магаражжиа нарын үзэж буйгаар, уг дохио нь оддын мөхлөөр бус, харин Их тэсрэлтийн дараах эрс тэс орчинд үүссэн анхдагч хар нүхнүүдээс үүдэлтэй байх магадлалтай юм.
Энэхүү онол батлагдвал орчлон ертөнцийн материйн 85 орчим хувийг бүрдүүлдэг боловч өнөөг хүртэл нууц хэвээр байгаа “харагддаггүй матери” буюу харанхуй материйн мөн чанарыг тайлбарлах чухал түлхүүр болох юм. Анх Яков Зельдович, Игорь Новиков нар дэвшүүлж, Стивен Хокинг хөгжүүлсэн энэхүү таамаглал нь олон арван жилийн турш туршилтаар батлагдаагүй байв.
Судлаачид “The Astrophysical Journal” сэтгүүлд нийтлүүлсэн бүтээлдээ, ийм төрлийн хар нүхнүүд ховор байх ёстой бөгөөд одоогийн ажиглалттай энэ нь нийцэж байгааг тэмдэглэжээ. Гэсэн хэдий ч ганц дохиог бүрэн нотолгоо гэж үзэх боломжгүй тул цаашид илүү олон ажиглалт хийх шаардлагатай гэж тэд анхааруулж байна.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A strange gravitational-wave signal detected by LIGO has reignited interest in one of cosmology’s most persistent theories. Researchers at the University of Miami believe the event may be evidence of a primordial black hole, a hypothetical object thought to have formed in the first moments after the Big Bang.
Primordial black holes are unlike the black holes astronomers typically study. Most known black holes are created when massive stars collapse at the end of their lives. They, by contrast, are believed to have formed much earlier, during the extreme conditions that existed shortly after the birth of the universe.
The idea has been around for decades, yet no primordial black hole has ever been confirmed. Their potential importance goes beyond black hole physics. Many researchers have suggested they could help explain dark matter, which accounts for about 85 percent of the universe’s matter and plays a major role in holding galaxies together through gravity.
A Signal Unlike Known Black Holes
The new study was sparked by an unusual gravitational-wave event detected by the Laser Interferometer Gravitational-Wave Observatory, or LIGO. Gravitational waves are ripples in spacetime produced by powerful cosmic events such as black hole mergers.
Late last year, LIGO issued an automated alert for a merger involving at least one object with a mass lower than that of the Sun. That detail immediately stood out because standard models of stellar evolution do not predict black holes with such low masses.
“The most common black holes form as the result of a supernova, the death of a massive star. So, their masses can range from a few times the Sun’s mass to billions of solar masses,” said Nico Cappelluti, an associate professor in the University of Miami’s Department of Physics.
The signal has not settled the debate. Some astrophysicists caution that it could still turn out to be noise in LIGO’s detectors. Yet the event remains difficult to explain through conventional astrophysical processes.
Evidence of a Primordial Black Hole?
Cappelluti and PhD student Alberto Magaraggia examined whether the signal could be explained by a primordial black hole formed in the dense environment of the early universe.
Their findings, published in The Astrophysical Journal, suggest that this interpretation fits the available evidence. The team also estimated how many of them may exist and how often instruments should be able to detect them.
“We attempted to estimate how many primordial black holes may exist in the universe and how many of them LIGO should be able to detect,” Magaraggia explained. “And our results are encouraging. We predict that subsolar black holes like the one LIGO may have observed should indeed be rare, consistent with how infrequently such events have been seen so far.”
The researchers found that low-mass primordial black holes should be uncommon, a result that matches the scarcity of similar signals in gravitational-wave observations to date.
A Decades-old Theory Gets A Fresh Test
The idea of primordial black holes was first proposed by Soviet scientists Yakov Zeldovich and Igor Novikov, before being further developed by Stephen Hawking, who suggested they could help explain dark matter.
For decades, the theory remained untested. That changed with the rise of gravitational-wave astronomy and the first direct detection of gravitational waves by LIGO in 2015.
Researchers behind the new study caution that a single event is not enough to confirm the existence of primordial black holes. Similar detections will be needed before scientists can reach a definitive conclusion.
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